Browser Automation for Agents Arena
Stagehand vs Smooth
Stagehand
Browserbase, Inc.
Stagehand wins · 16–7 (23 drawn)
Action primitives — stories about action primitives in this arenaAction primitives
Stories about action primitives in this arena
Caching
developerCache resolved actions or generated code so repeat runs replay deterministically at lower cost and latency than re-prompting the LLM
weight 2 · round to StagehandStagehand's docs explicitly state that act(), observe(), and extract() results are cached server-side to reduce LLM costs and speed up automations, directly matching the story's request for cached deterministic replay at lower cost/latency. Additional support for persistent user data (cookies/local storage, Browserbase contexts) reinforces cross-run determinism, though there's no independent/hands-on corroboration of cache-hit behavior or cache invalidation details. Missing for 10: independent verification of caching effectiveness/determinism claims, details on cache invalidation when page structure changes, and quantified latency/cost savings.
- [claimed-docs] “Stagehand caches `act()`, `observe()`, and `extract()` results server-side to reduce LLM costs and speed up your automations.”
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
Smoothnone0/10No evidence of caching resolved actions/generated code for deterministic, cheaper replay; docs mention persistent sessions (auth reuse), structured outputs, and cost efficiency via small models, but nothing about caching or replay of prior task executions to skip re-prompting the LLM. Missing for 10: any mention of action/result caching, replay mechanism, or cost/latency comparison for repeat runs.
- [claimed-docs] “Log in once, then reuse that authentication for future tasks.”
- [claimed-docs] “Structured outputs allow you to write deterministic code based on the agent's output. To activate structured outputs, set the `response_mode…”
- [claimed-docs] “Smooth uses small and efficient AI models, making it 7x more affordable than browser-use.”
Dom
developerDrive the page through DOM-understanding action primitives (act/click/type on described elements) that survive selector and layout changes
weight 3 · round to StagehandDocs describe act()/observe()/extract() as natural-language, DOM-understanding primitives with selfHeal to re-infer broken selectors and automatic iframe/shadow-DOM handling, directly matching the story; independent HN commentary corroborates that Stagehand dynamically regenerates Playwright actions making it resilient to DOM changes. Missing for 10: rigorous independent benchmark of resilience across real layout changes and more than a single third-party account.
- [claimed-docs] “Execute actions using natural language”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “Turn on `selfHeal` to re-infer an action when its recorded selector breaks.”
- [claimed-docs] “Stagehand automatically handles iFrame traversal and shadow DOM elements without requiring additional configuration.”
- [community] “Playwright codegen is incredibly powerful, but still pretty brittle. Its DOM selectors are still hardcoded... With Stagehand, the code is se…”
Smooth's docs describe a 'Session Workflow' that lets you orchestrate smaller tasks, navigate to URLs, and extract data within a persistent session, and the whole product is framed as an AI browser agent that understands pages rather than relying on brittle selectors (smooth-docs-7, smooth-gh-1). However, there is no explicit documentation of discrete act/click/type primitives on described elements, nor any evidence/testing showing these survive selector or layout changes — community comments even note it doesn't fully close the gap versus Playwright-style tools (smooth-comm-8). Missing for 10: explicit act/click/type API reference, documented resilience testing against DOM/selector changes, independent verification of robustness claims.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [community] “agent-browser helped a lot over playwright but doesn't completely close the gap.”
Observe
developerPreview candidate actions on the current page (observe/plan) before committing the agent to act
weight 1 · round to Stagehandobserve() is a first-class primitive documented explicitly for discovering actionable elements and returning structured actions 'you can execute or validate before acting,' directly matching the preview/plan-before-act story, and it composes with act()/extract() as separate committed steps (stagehand-docs-3). Runtime probe confirms the package installs and exposes the Stagehand class in practice. missing for 10: independent hands-on developer confirmation specifically of observe()'s preview behavior (community evidence discusses self-healing/act() but not observe() directly).
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “Execute actions using natural language”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
Vision
developerSwitch to a vision or computer-use action mode that operates on screenshots for canvases and UIs the DOM path can't handle
weight 2 · round drawnStagehandnone0/10No documentation describes a vision/computer-use mode operating on screenshots; the only related evidence is a community comment stating the team is 'working on a better computer use integration' — implying it isn't shipped yet.
- [community] “Our Stagehand MCP server actually won Anthropic's Claude MCP hackathon :) ... We're working on a better computer use integration using Stage…”
Smoothnone0/10The evidence pack covers Smooth's session workflows, extraction, custom tools, proxies, and CAPTCHA solving, but nowhere mentions a vision/computer-use mode operating on screenshots for canvases or non-DOM UI elements. This axis is plausible for a browser-automation agent, but no documentation or community report confirms such a capability exists.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
Agenticness — how well agents can access and operate the productAgenticness
How well agents can access and operate the product
Agent access
ai-native userPoint an agent at llms.txt or agent-oriented docs
weight 2 · round drawnThe probe confirms Stagehand's docs site serves a valid llms.txt (HTTP 200) with structured links to docs pages, directly enabling an agent to be pointed at agent-oriented documentation. missing for 10: no evidence of independent/community confirmation that agents actually consume this llms.txt successfully in practice, and no detail on completeness/coverage of the llms.txt beyond the introduction page.
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.stagehand.dev/llms.txt # Stagehand - [Introducing Stagehand](https://docs.stagehand.dev/v4/first-s…”
A direct probe confirms docs.smooth.sh/llms.txt returns HTTP 200 with a structured index of docs pages, and the docs themselves are mirrored as .md files (e.g. live-share.md, proxies.md) enabling agent-friendly consumption. One community comment notes the docs pages aren't fully token-efficient, a minor caveat. Missing for 10: independent verification that agents actually consume llms.txt effectively, and no evidence of additional agent-specific doc formats beyond the single llms.txt file.
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
- [claimed-docs] “Log in once, then reuse that authentication for future tasks.”
- [community] “Ironically, the landing page and docs pages of Smooth aren't all that token-efficient!”
ai-native userRun the product headlessly / in CI for automation
weight 2 · round to StagehandStagehand is a Node/TS library built on Playwright with a scriptable API (act/observe/extract), headless browser support via Browserbase or CDP-attached Chromium, and npm-installable package confirmed via runtime probe, making CI/headless automation straightforward. missing for 10: explicit first-party CI pipeline examples (GitHub Actions/Docker recipes) and independent hands-on confirmation of a full unattended CI run.
- [claimed-docs] “When you know the selector or want zero inference, use page methods you already know.”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
- [claimed-docs] “Attach over CDP (localBrowser.connect): Attach to any Chromium browser you are already running, by URL”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
- [community] “Have been on the Slack for a while and this crew has had an insane product velocity. Excited to see where it goes!”
Smooth is explicitly designed as an SDK/API and CLI for programmatic browser automation, with 'plug-and-play' 4-line-of-code task execution and custom tools/session workflows suited to unattended automation, and a documented CLI (smooth-gh-1, smooth-docs-1, smooth-probe-3). However there is no explicit documentation or example of running it inside a CI pipeline (e.g., GitHub Actions), headless flags, or exit-code/automation-specific guidance. Missing for 10: explicit CI/CD integration docs or examples, confirmation of non-interactive/headless auth flow for pipelines, independent confirmation of CI usage.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [probe] “official CLI documented at https://docs.smooth.sh/cli/overview”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
ai-native userPlug MCP servers into this product so it can use their tools
weight 3 · round drawnStagehandnone0/10All evidence shows Stagehand exposing its own browser-automation tools via MCP (server role) to other agents like Claude Code, not Stagehand acting as an MCP client that consumes external MCP servers' tools. No evidence describes configuring Stagehand to plug into third-party MCP servers so it can call their tools.
- [claimed-docs] “Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio.”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
Smoothnone0/10Smooth documents a 'custom tools' feature for arbitrary functions but there is no mention anywhere in docs, GitHub, or community discussion of MCP server support or integration, so this applicable capability is unevidenced.
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
ai-native userConnect an agent via an official MCP server
weight 3 · round to StagehandStagehand ships an official MCP server ('Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio') and a runtime probe confirms `npx -y @browserbasehq/mcp` actually boots and identifies as 'Browserbase MCP Server ... powered by Browserbase and Stagehand', responding to JSON-RPC initialize. Community evidence corroborates real-world use (the Stagehand MCP server won Anthropic's Claude MCP hackathon). Missing for 10: independent third-party review of the full tool surface/robustness of the MCP server beyond the hackathon anecdote and the first-party docs/probe.
- [claimed-docs] “Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio.”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
- [community] “Our Stagehand MCP server actually won Anthropic's Claude MCP hackathon :) ... We're working on a better computer use integration using Stage…”
Smoothnone0/10Smooth is a browser-automation SDK/CLI used by agents like Claude Code, but the evidence pack contains no mention of an official MCP server or MCP protocol integration anywhere in its docs, GitHub repo, or community discussion — only generic SDK/CLI methods and custom tool functions are documented.
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
- [probe] “official CLI documented at https://docs.smooth.sh/cli/overview”
ai-native userUse an official CLI
weight 2 · round to SmoothStagehandnone0/10Stagehand is distributed as an npm SDK/library plus an MCP server; the evidence pack shows npm install and MCP server invocation via npx, but no dedicated official CLI tool for direct AI-native command-line interaction is documented anywhere.
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
- [claimed-docs] “Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio.”
GitHub repo describes Smooth CLI explicitly as 'a browser for AI agents, enabling tools like Claude Code to navigate the web' and a docs probe confirms an official CLI overview page exists, showing a first-party CLI built for AI-agent workflows. Missing for 10: independent hands-on confirmation of the CLI's usage/reliability and more detailed CLI documentation content beyond the overview link.
ai-native userDrive the product through a documented public API
weight 3 · round to StagehandStagehand ships a well-documented public SDK API (act(), extract(), observe(), page methods, selfHeal, caching) with a dedicated docs site and llms.txt, and an npm package that a runtime probe confirms actually installs and exports a working class plus a functioning MCP server exposing the same tools. Community posts corroborate real developer usage of this API for browser automation. Missing for 10: an OpenAPI/REST spec (404s) and deeper independent (non-community) validation of API stability/versioning.
- [claimed-docs] “Execute actions using natural language”
- [claimed-docs] “extract() grabs structured data from a webpage. Every call takes an instruction and an output shape”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “When you know the selector or want zero inference, use page methods you already know.”
- [claimed-docs] “Turn on `selfHeal` to re-infer an action when its recorded selector breaks.”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.stagehand.dev/llms.txt # Stagehand - [Introducing Stagehand](https://docs.stagehand.dev/v4/first-s…”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.stagehand.dev/openapi.json, https://docs.stagehand.dev/swagger.json, https://docs.stage…”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
- [community] “Playwright codegen is incredibly powerful, but still pretty brittle. Its DOM selectors are still hardcoded... With Stagehand, the code is se…”
Smooth provides documented SDK/API methods (task execution, session workflows, structured outputs, custom tools, proxies) and an llms.txt docs index plus a CLI, showing a documented programmatic interface for AI-native use. However, no formal OpenAPI/REST spec was found (404s on all standard paths), and there is no independent corroboration of API robustness beyond vendor docs. missing for 10: a discoverable OpenAPI/REST spec, independent/hands-on verification of API completeness and stability.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.smooth.sh/openapi.json, https://docs.smooth.sh/swagger.json, https://docs.smooth.sh/api…”
- [probe] “official CLI documented at https://docs.smooth.sh/cli/overview”
ai-native userIssue scoped/least-privilege API credentials for an agent
weight 2 · round drawnStagehandnone0/10Stagehand is a browser-automation library; evidence covers API keys for model/Browserbase access but no scoped/least-privilege credential issuance, role-based permissions, or token-scoping features for agents are documented anywhere in docs, community, or probes. Missing for 10: any mention of scoped API key issuance, permission scoping, or least-privilege credential management for agents.
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
Smoothnone0/10No evidence of scoped or least-privilege API credential issuance, API key scoping, or permission management for agents; docs cover task execution, sessions, proxies, and privacy features but nothing about credential scoping. missing for 10: scoped API key/token generation, permission/role controls, credential revocation or least-privilege access management.
ai-native userBuild against official SDKs
weight 2 · round to StagehandStagehand ships an official TypeScript/JS SDK (@browserbasehq/stagehand npm package) with documented APIs (act, observe, extract) and confirmed runtime install/import success, making it directly usable by AI-native developers building agentic browser automation. missing for 10: no evidence of official SDKs in other languages (e.g., Python) or independent third-party corroboration of SDK API stability beyond docs and one runtime probe.
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
- [claimed-docs] “extract() grabs structured data from a webpage. Every call takes an instruction and an output shape”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “Execute actions using natural language”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.stagehand.dev/llms.txt # Stagehand - [Introducing Stagehand](https://docs.stagehand.dev/v4/first-s…”
Smooth documents SDK-style integration (4-line task execution, custom tools, structured outputs, session workflows) and a CLI positioned as "a browser for AI agents" usable with tools like Claude Code, indicating official first-party SDK/CLI support for AI-native workflows. However, there is no OpenAPI spec, no evidence of multi-language SDKs, and no independent/hands-on confirmation of SDK reliability beyond docs and a GitHub repo. missing for 10: OpenAPI/API spec availability, multi-language SDK coverage, independent developer corroboration of SDK usage/quality.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [probe] “official CLI documented at https://docs.smooth.sh/cli/overview”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.smooth.sh/openapi.json, https://docs.smooth.sh/swagger.json, https://docs.smooth.sh/api…”
Agentic features
ai-native userSet up automations that run autonomously in the background
weight 2 · round drawnStagehand supports cloud-hosted Browserbase sessions with persistent user data/contexts, caching to speed repeat runs, and a real-time observability dashboard, all of which enable automations to run without a local machine and be monitored asynchronously. However there's no documented scheduler, trigger system, or explicit 'run unattended over time' capability distinguishing this from any scripted automation run on-demand. missing for 10: explicit scheduling/cron or trigger mechanism, evidence of long-running unattended multi-step autonomous sessions, independent confirmation of background execution reliability.
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
- [claimed-docs] “Browserbase provides real-time visibility into your automation sessions: **Session dashboard features** * Real-time browser screen recordi…”
- [claimed-docs] “Stagehand caches `act()`, `observe()`, and `extract()` results server-side to reduce LLM costs and speed up your automations.”
Smooth lets users kick off browser-agent tasks programmatically that run autonomously (navigating, extracting data, solving CAPTCHAs) and provides a live_url to monitor progress, which supports hands-off execution once started. However there's no evidence of scheduling, triggers, webhooks, or persistent 'set it and forget it' background jobs that run without an explicit API call — the model shown is synchronous task invocation, not autonomous background automation setup. Missing for 10: scheduling/cron or event-trigger support, evidence of long-running unattended jobs, and independent confirmation of background execution beyond a single task call.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Auto-CAPTCHA solvers: Bypass CAPTCHA challenges automatically, allowing for uninterrupted task execution.”
ai-native userDelegate tasks to a built-in AI assistant inside the product
weight 3 · round drawnStagehand's core capability is letting an AI-native user delegate actions to a built-in AI (act/extract/observe) via natural language, with self-healing and DOM handling reducing manual work — this is the product's central value proposition and is corroborated by community praise for its natural-language automation and self-healing behavior. missing for 10: independent quantitative benchmarks of task delegation success/reliability and more explicit UI/chat-assistant framing beyond programmatic act()/extract() calls.
- [claimed-docs] “Execute actions using natural language”
- [claimed-docs] “extract() grabs structured data from a webpage. Every call takes an instruction and an output shape”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “Turn on `selfHeal` to re-infer an action when its recorded selector breaks.”
- [claimed-docs] “Stagehand automatically handles iFrame traversal and shadow DOM elements without requiring additional configuration.”
- [community] “Playwright codegen is incredibly powerful, but still pretty brittle. Its DOM selectors are still hardcoded... With Stagehand, the code is se…”
- [community] “I've been playing around with Stagehand for a minute now, actually a useful abstraction here. We build scrapers for websites that are pretty…”
Smooth's core product is a task-delegation interface: users hand off a task description (e.g., navigate, extract, multi-step session workflow) to Smooth's built-in AI/browser agent, which executes autonomously and returns live_url and structured outputs (smooth-docs-1, smooth-docs-7, smooth-docs-8, smooth-docs-5). Community hands-on feedback corroborates it executing complex prompts well (smooth-comm-2, smooth-comm-1), though it is agent-facing (tool for other agents like Claude Code) as well as human-facing. Missing for 10: independent/reproducible benchmarks of task success (raised unanswered in smooth-comm-14) and clearer human-only assistant UX beyond API/CLI task calls.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
- [claimed-docs] “Structured outputs allow you to write deterministic code based on the agent's output. To activate structured outputs, set the `response_mode…”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
- [community] “Super impressive demo. Seems a lot faster than alternatives. How did you achieve that?”
- [community] “I just wrote a complex prompt and it did a good job. How do you do evals or testing of your project?”
ai-native userOperate the product with natural-language commands
weight 2 · round to StagehandStagehand's core API (act/extract/observe) is explicitly designed around natural-language instructions instead of hardcoded selectors, with docs describing instruction-driven execution and self-healing when selectors break. Community commentary independently corroborates that this NL-driven approach dynamically generates Playwright actions and is more resilient than traditional automation frameworks. Missing for 10: independent quantitative benchmarks on NL command accuracy/reliability across diverse sites.
- [claimed-docs] “Execute actions using natural language”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “Turn on `selfHeal` to re-infer an action when its recorded selector breaks.”
- [claimed-docs] “Traditional selectors break when websites change”
- [community] “Playwright codegen is incredibly powerful, but still pretty brittle. Its DOM selectors are still hardcoded... With Stagehand, the code is se…”
Smooth's core interaction model is task-based: you give it a task description that an agent executes in a browser (session workflow, extract, navigate), and it is explicitly positioned as "a browser for AI agents" usable by tools like Claude Code, implying natural-language task instructions. However, no evidence shows an explicit example of a natural-language prompt/command syntax or confirms this is exposed to end-users beyond agent-to-agent orchestration. Missing for 10: explicit example of a natural-language task string/command, confirmation of human-facing NL command interface, independent corroboration of NL usability.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
Api quality
ai-native userExplore an interactive API reference with runnable examples
weight 2 · round drawnStagehandnone0/10The evidence pack shows standard prose documentation pages (docs.stagehand.dev) and confirms no OpenAPI/swagger spec exists (404s on all candidate paths), with no mention anywhere of an interactive, runnable-example API reference (e.g., live code sandbox or Swagger-style explorer). The llms.txt probe only shows a docs index for LLM ingestion, not an interactive reference.
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.stagehand.dev/openapi.json, https://docs.stagehand.dev/swagger.json, https://docs.stage…”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.stagehand.dev/llms.txt # Stagehand - [Introducing Stagehand](https://docs.stagehand.dev/v4/first-s…”
- [claimed-docs] “Execute actions using natural language”
Smoothnone0/10The evidence pack shows only static markdown docs (llms.txt, feature pages) and explicitly shows the openapi.json/swagger endpoints returning 404, indicating no interactive API reference or runnable-example playground exists. No mention of a Swagger UI, Postman collection, or in-browser code runner is present anywhere in docs or community discussion.
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.smooth.sh/openapi.json, https://docs.smooth.sh/swagger.json, https://docs.smooth.sh/api…”
ai-native userDownload a machine-readable API spec (OpenAPI or equivalent)
weight 2 · round drawnStagehandnone0/10Direct probes for OpenAPI/swagger specs at all standard paths returned 404, and no documentation mentions a downloadable machine-readable API spec; only an llms.txt exists which is not an API spec.
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.stagehand.dev/openapi.json, https://docs.stagehand.dev/swagger.json, https://docs.stage…”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.stagehand.dev/llms.txt # Stagehand - [Introducing Stagehand](https://docs.stagehand.dev/v4/first-s…”
Smoothnone0/10A direct probe for OpenAPI/Swagger spec files at all standard paths returned 404, and no docs page references a downloadable machine-readable API spec; only an llms.txt (docs index) is available.
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.smooth.sh/openapi.json, https://docs.smooth.sh/swagger.json, https://docs.smooth.sh/api…”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
ai-native userTest against a sandbox environment without touching production data
weight 1 · round drawnStagehandnone0/10Stagehand's docs cover browser session persistence, regions, and observability but nothing about a dedicated sandbox/staging mode or safeguards to prevent hitting production data; the evidence pack shows only live browser automation against real or Browserbase-hosted sites.
Smoothnone0/10Smooth's docs describe browser-automation features (live sessions, proxies, persistent auth, structured outputs) but nowhere mention a sandbox/staging mode or any mechanism to isolate test runs from production data or accounts. Community feedback even flags unresolved concerns about data handling and security, but no concrete sandbox capability is described or corroborated.
ai-native userRely on versioned APIs with a documented deprecation policy
weight 2 · round drawnStagehandnone0/10Docs reference a 'v4' version path, but there is no evidence of a documented API versioning scheme or deprecation policy for Stagehand's SDK/API; no openapi spec or changelog/deprecation docs were found (openapi probe 404s).
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.stagehand.dev/openapi.json, https://docs.stagehand.dev/swagger.json, https://docs.stage…”
Smoothnone0/10No evidence of API versioning scheme or a documented deprecation policy; OpenAPI spec probe returned 404s and docs show no changelog/versioning references. missing for 10: versioned API scheme, deprecation policy documentation, changelog/migration guides.
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.smooth.sh/openapi.json, https://docs.smooth.sh/swagger.json, https://docs.smooth.sh/api…”
Auth session persistence — stories about auth session persistence in this arenaAuth session persistence
Stories about auth session persistence in this arena
Compat
developerConnect my existing Playwright, Puppeteer, or CDP automation code to the product's browsers instead of rewriting it
weight 2 · round to StagehandStagehand explicitly supports attaching over CDP to any existing Chromium browser and lets you keep using familiar page-level (Playwright) methods when you don't need AI inference, which lets developers reuse existing Playwright/CDP automation rather than rewriting from scratch. However there is no evidence of native Puppeteer script compatibility, and community comments note Stagehand is positioned as a replacement/wrapper rather than a drop-in for arbitrary existing Playwright suites. Missing for 10: explicit Puppeteer interop, first-party guide on migrating existing Playwright test suites unmodified, and independent confirmation that CDP-attach preserves auth/session state seamlessly.
- [claimed-docs] “Attach over CDP (localBrowser.connect): Attach to any Chromium browser you are already running, by URL”
- [claimed-docs] “When you know the selector or want zero inference, use page methods you already know.”
- [community] “Playwright codegen is incredibly powerful, but still pretty brittle. Its DOM selectors are still hardcoded... With Stagehand, the code is se…”
- [community] “This looks very cool and makes a lot of sense, except for the idea that it should take the place of Playwright et al. Personally I'd love to…”
Smoothnone0/10Smooth's docs describe its own SDK/task API (structured outputs, sessions, custom tools) but there is no mention of a CDP endpoint, Playwright/Puppeteer connect() compatibility, or any way to point existing automation code at Smooth's browsers; one commenter even notes 'agent-browser helped a lot over playwright but doesn't completely close the gap,' underscoring the absence of such interoperability. Missing for 10: any CDP/WebSocket endpoint, official Playwright/Puppeteer connect examples, or documented browser-endpoint compatibility.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Set to `"self"` to create a P2P tunnel through your machine, routing traffic via your IP and enabling access to localhost.”
- [community] “agent-browser helped a lot over playwright but doesn't completely close the gap.”
Credentials
automation-engineerStore credentials in a vault and have the agent complete logins including TOTP/2FA challenges without exposing secrets to the model
weight 2 · round drawnStagehandnone0/10Evidence covers session/state persistence (cookies, local storage, Browserbase contexts) but there is no mention of vault-based credential storage, secret injection to avoid model exposure, or TOTP/2FA handling anywhere in the docs or community evidence.
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
Smoothnone0/10The docs describe persistent sessions (log in once, reuse authentication) but there is no mention of a credential vault, secret injection to avoid model exposure, or TOTP/2FA handling anywhere in the evidence pack. This axis clearly applies to a browser-automation agent product, but no capability matching the story is documented.
- [claimed-docs] “Log in once, then reuse that authentication for future tasks.”
Profiles
developerPersist logged-in browser state in reusable profiles so agents skip the login wall on every subsequent run
weight 3 · round to StagehandDocs explicitly describe persisting local browser user-data directories (cookies/local storage survive across runs) and Browserbase contexts for persisting session/browser data across cloud runs, directly matching the reusable-profile/login-skip story. Missing for 10: independent hands-on confirmation that a persisted profile actually skips a real login wall, and more detail on context lifecycle/expiry limits.
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
Smooth's docs explicitly describe a persistent-sessions feature ('Log in once, then reuse that authentication for future tasks') and a session workflow that maintains a persistent browser session across multi-step tasks, directly matching the story. However, there is no independent/hands-on corroboration of this specific feature working reliably, and no detail on profile management (multiple reusable profiles, storage/export). Missing for 10: independent verification of session persistence in practice, documentation on managing multiple reusable profiles.
- [claimed-docs] “Log in once, then reuse that authentication for future tasks.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
Automation depth — how much of the product can run unattendedAutomation depth
How much of the product can run unattended
ai-native userPerform bulk operations across many items at once
weight 2 · round drawnStagehandnone0/10The evidence pack covers single-page act/extract/observe primitives, caching, and session persistence, but nothing describes batch/bulk operations across many items or parallelized runs at once. A browser-automation framework could plausibly support this (e.g., running many sessions in parallel), so the axis applies, but no such capability is documented.
Smoothnone0/10Smooth's docs describe single-task execution, session workflows, and structured extraction, but nothing about running/orchestrating bulk operations across many items (e.g., batch task queues, parallel task fan-out) is documented or mentioned by users.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
Deployment modes — stories about deployment modes in this arenaDeployment modes
Stories about deployment modes in this arena
Local
developerRun the agent against a local browser on my own machine for development, without any cloud account
weight 2 · round to StagehandDocs confirm Stagehand can attach to a local Chromium browser over CDP (localBrowser.connect) and persist local user data on disk, meaning it can run fully locally without Browserbase/cloud accounts; Browserbase is presented as optional rather than required. missing for 10: independent hands-on confirmation of a pure-local run with no cloud account, and clearer docs distinguishing local-only setup from Browserbase defaults.
- [claimed-docs] “Attach over CDP (localBrowser.connect): Attach to any Chromium browser you are already running, by URL”
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
- [claimed-docs] “When you know the selector or want zero inference, use page methods you already know.”
Smoothnone0/10Smooth is documented as a cloud-hosted browser agent service (task execution via live_url, proxies, zero-data-retention as an 'enterprise' add-on), with no docs describing a local-browser/offline mode; a P2P tunnel feature only lets the cloud agent reach your localhost, not run without an account. Community feedback explicitly asks for self-hosting ('Make it self-hostable, the conversation can change'), confirming no local/no-account mode exists.
- [claimed-docs] “Zero Data Retention is an enterprise feature that provides enhanced data privacy by allowing you to delete all data associated with complete…”
- [claimed-docs] “Set to `"self"` to create a P2P tunnel through your machine, routing traffic via your IP and enabling access to localhost.”
- [community] “I'm unwilling to send my data to a 3rd party that is so new on the scene... Make it self-hostable, the conversation can change”
- [community] “Way too expensive, I'll wait for a free/open source browser optimized to be used by agents.”
Framework model support — stories about framework model support in this arenaFramework model support
Stories about framework model support in this arena
Frameworks
developerPlug the browser layer into agent frameworks (Claude Agent SDK, Vercel AI SDK, LangChain, CrewAI) through documented adapters
weight 2 · round to StagehandDocs and community evidence confirm a documented MCP/stdio integration for Claude Code agents (and a Browserbase MCP server actually powered by Stagehand), but there is no evidence of documented adapters for Vercel AI SDK, LangChain, or CrewAI as the story specifically requires. missing for 10: Vercel AI SDK adapter docs, LangChain adapter docs, CrewAI adapter docs, and any first-party guide unifying these framework integrations.
- [claimed-docs] “Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio.”
- [community] “Our Stagehand MCP server actually won Anthropic's Claude MCP hackathon :) ... We're working on a better computer use integration using Stage…”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
Smoothnone0/10Evidence shows Smooth positions itself as a browser tool usable by agents like Claude Code, but there is no documentation of adapters for Claude Agent SDK, Vercel AI SDK, LangChain, or CrewAI specifically. Missing for 10: any documented integration guide or adapter package for these named frameworks.
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
Models
developerBring my own LLM provider — the framework is model-agnostic rather than locked to one vendor's models
weight 2 · round drawnStagehandnone0/10The evidence pack never documents which LLM providers Stagehand supports or describes any provider-swapping configuration; it only notes that a 'model key' is required to run (stagehand-probe-rt-1), without specifying that multiple vendors' models are interchangeable. Missing for 10: any docs or examples showing configuration for OpenAI/Anthropic/other providers, a provider-agnostic API surface, or community confirmation of using non-default models.
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
Smoothnone0/10Smooth's docs describe it as using its own internal 'small and efficient AI models' for browser-agent tasks, and none of the documentation, CLI, or API references mention any mechanism for developers to configure or swap in their own LLM provider (e.g., OpenAI, Anthropic, custom model endpoints). This suggests the opposite of model-agnosticism — the models are an implementation detail of the service, not a pluggable choice.
- [claimed-docs] “Smooth uses small and efficient AI models, making it 7x more affordable than browser-use.”
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [probe] “PROBE llms.txt: HTTP 200 at https://docs.smooth.sh/llms.txt # Smooth ## Docs - [Introduction](https://docs.smooth.sh/index.md): Welcome to…”
Nl task execution — stories about nl task execution in this arenaNl task execution
Stories about nl task execution in this arena
Tasks
ai agentSubmit a browser task over a hosted HTTP API and receive the result by polling or webhook, without managing any browser myself
weight 2 · round to SmoothStagehandnone0/10Stagehand is presented as an SDK/library (with an MCP server for agent tool-use) rather than a hosted HTTP task-submission API; the probe explicitly found no OpenAPI/REST endpoint (openapi paths all 404), and no docs describe submitting a task and polling or receiving a webhook result. Evidence shows Browserbase-hosted browser sessions and MCP/stdio integration, but nothing matching the described async HTTP task API.
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.stagehand.dev/openapi.json, https://docs.stagehand.dev/swagger.json, https://docs.stage…”
- [claimed-docs] “Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio.”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
Docs confirm a hosted task-submission model (4-line integration, live_url for tracking, persistent sessions, structured outputs) consistent with an agent submitting tasks without managing a browser, but no evidence pack item explicitly documents a polling endpoint or webhook delivery mechanism, and probes found no public OpenAPI/REST spec. missing for 10: explicit polling endpoint docs, explicit webhook/callback docs, confirmed REST API schema (openapi probe 404s).
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [probe] “PROBE openapi: all candidate paths 404 (https://docs.smooth.sh/openapi.json, https://docs.smooth.sh/swagger.json, https://docs.smooth.sh/api…”
- [probe] “official CLI documented at https://docs.smooth.sh/cli/overview”
developerHand the product a natural-language goal and it completes a multi-step web task end to end — navigating, filling forms, and clicking through flows
weight 3 · round to SmoothStagehand's docs confirm natural-language act()/observe()/extract() primitives that can navigate, click, and fill forms, plus self-healing and iframe/shadow-DOM handling that support robustness across steps, and community posts confirm real-world scraping/automation use (stagehand-comm-1, stagehand-comm-9). However, the evidence shows these as composable single-action primitives rather than a documented single-call 'give it a goal and it autonomously completes a multi-step flow' agent mode — multi-step chains appear to require the developer to sequence act/observe/extract calls or wire it via MCP into another agent (stagehand-docs-11). Missing for 10: first-party or hands-on evidence of a single natural-language goal driving full end-to-end multi-step task completion without developer-orchestrated step chaining.
- [claimed-docs] “Execute actions using natural language”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “Turn on `selfHeal` to re-infer an action when its recorded selector breaks.”
- [claimed-docs] “Stagehand automatically handles iFrame traversal and shadow DOM elements without requiring additional configuration.”
- [claimed-docs] “Give a Claude Code agent persistent Stagehand browser tools over MCP/stdio.”
- [community] “I've been playing around with Stagehand for a minute now, actually a useful abstraction here. We build scrapers for websites that are pretty…”
- [community] “Playwright codegen is incredibly powerful, but still pretty brittle. Its DOM selectors are still hardcoded... With Stagehand, the code is se…”
Docs describe exactly this capability: multi-step 'Session Workflow' that navigates URLs, orchestrates sub-tasks, and extracts data, plus a live_url to watch the agent act, and a community commenter confirms 'I just wrote a complex prompt and it did a good job.' This matches the natural-language, end-to-end web task story well. Missing for 10: independently reproducible benchmarks/evals (a commenter explicitly asks for third-party reproducible comparisons and gets no clear answer), and broader hands-on validation beyond a single anecdote.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
- [community] “I just wrote a complex prompt and it did a good job. How do you do evals or testing of your project?”
- [community] “are your evals / comparisons publicly/3rd party reproducible? If it's 'trust me, I did a fair comparison', that's not going to fly today.”
Workflows
automation-engineerCompose repeatable multi-step workflows with loops, conditionals, and parameters instead of one-shot prompts
weight 2 · round to StagehandStagehand is a code-first SDK (act/observe/extract primitives) that developers embed in regular TypeScript/Python code, which implicitly allows loops, conditionals, and parameters since it's just function calls in a host language — but no docs explicitly describe workflow composition, control-flow patterns, or parameterized repeatable workflows as a first-class feature. missing for 10: explicit workflow/orchestration documentation, examples of loops or conditionals chaining act/observe/extract calls, parameterized workflow templates, and any community evidence of engineers building such multi-step conditional workflows.
- [claimed-docs] “extract() grabs structured data from a webpage. Every call takes an instruction and an output shape”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
- [claimed-docs] “When you know the selector or want zero inference, use page methods you already know.”
- [claimed-docs] “Stagehand caches `act()`, `observe()`, and `extract()` results server-side to reduce LLM costs and speed up your automations.”
Smooth documents a 'Session Workflow' method for multi-step execution—orchestrating smaller tasks, navigating URLs, and extracting data within a persistent browser session—plus structured outputs and custom tools that let developers build deterministic logic around agent calls. However, there is no explicit documentation of native loop/conditional constructs or parameterized workflow templates; any control flow would rely on the surrounding SDK code rather than a built-in workflow engine. Missing for 10: explicit loop/conditional primitives, parameterization/templating of workflows, and independent evidence of repeatable multi-step automations beyond simple session chaining.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Structured outputs allow you to write deterministic code based on the agent's output. To activate structured outputs, set the `response_mode…”
- [claimed-docs] “Custom tools allow you to give Smooth any arbitrary function as a tool.”
Openness — open source, data portability, and self-hosting storiesOpenness
Open source, data portability, and self-hosting stories
ai-native userExport all of my data in open formats and leave
weight 3 · round drawnStagehandnone0/10The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)
Smoothnone0/10Smooth's docs mention Zero Data Retention (deletion of task data) but there is no evidence of a bulk data export feature or open-format export for users to take their data and leave — the closest related item is deletion, not portability. missing for 10: any documented export mechanism, open format specification, or user data portability tooling.
- [claimed-docs] “Zero Data Retention is an enterprise feature that provides enhanced data privacy by allowing you to delete all data associated with complete…”
ai-native userRead the product's source under an open license
weight 2 · round drawnStagehandnone0/10The evidence pack contains only docs, community discussion, and runtime probes about Stagehand's automation features; none of it references a public source repository, license, or open-source status. Missing for 10: any mention of a GitHub repo, license file, or open-source claim.
Smoothnone0/10Smooth ships a GitHub repo for its SDK/CLI, but there is no evidence of an open-source license for the core product, and community comments explicitly request self-hosting/open-source alternatives ('Make it self-hostable, the conversation can change', 'I'll wait for a free/open source browser'), implying the core service is closed.
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [community] “I'm unwilling to send my data to a 3rd party that is so new on the scene... Make it self-hostable, the conversation can change”
- [community] “Way too expensive, I'll wait for a free/open source browser optimized to be used by agents.”
ai-native userSelf-host the core product
weight 3 · round to StagehandStagehand is installable via npm and can run against a locally-controlled Chromium instance via CDP (localBrowser.connect), and the runtime probe confirms local install/execution without requiring Browserbase credentials, indicating the core library can be self-hosted. However, several advanced features (proxies, captcha handling, session recording, multi-region hosting) are documented as Browserbase-cloud-only, and there is no explicit self-hosting/Docker deployment guide or licensing statement. Missing for 10: dedicated self-host deployment docs, confirmation that captcha/proxy features work without Browserbase, and independent hands-on confirmation of a fully self-hosted setup.
- [claimed-docs] “Attach over CDP (localBrowser.connect): Attach to any Chromium browser you are already running, by URL”
- [probe] “PROBE runtime (recorded 2026-09-04, see data/browser-agents/proofs/stagehand/): `npm install @browserbasehq/stagehand` completed and the ESM…”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
Smoothnone0/10Smooth is offered only as a hosted cloud API/SaaS with no documented self-host option, and community feedback explicitly requests self-hosting as a missing capability ('Make it self-hostable, the conversation can change').
- [community] “I'm unwilling to send my data to a 3rd party that is so new on the scene... Make it self-hostable, the conversation can change”
- [community] “My first question was whether I could use this for sensitive tasks, given that it's not running on our machines. And after poking around for…”
Pricing limits — free-tier ceilings, usage caps, and rate limits before you have to payPricing limits
Free-tier ceilings, usage caps, and rate limits before you have to pay
Pricing
developerSee transparent per-task or per-browser-hour pricing and documented rate/concurrency limits before committing
weight 2 · round drawnStagehandnone0/10No evidence pack items mention pricing tiers, per-task/per-browser-hour costs, or documented rate/concurrency limits — docs cover only technical features (caching, contexts, regions) and community comments are unrelated to pricing transparency.
Smoothnone0/10No evidence of documented per-task/per-browser-hour pricing tiers or rate/concurrency limits; only a vague claim of being '7x more affordable' with no actual pricing page or limits documented, and community comments call it 'too expensive' without citing specifics.
- [claimed-docs] “Smooth uses small and efficient AI models, making it 7x more affordable than browser-use.”
- [community] “Way too expensive, I'll wait for a free/open source browser optimized to be used by agents.”
- [community] “I'm paying a fixed amount on Claude and other agents, so 'more tokens' is 'free' for me. There's a lot of niche tools out there but I think …”
Privacy posture — data-handling and privacy storiesPrivacy posture
Data-handling and privacy stories
ai-native userChoose where my data is stored (region/residency)
weight 2 · round to StagehandDocs state Browserbase-hosted sessions can be started in one of four regions and that this can keep session data in a required jurisdiction, giving some data-residency control (stagehand-docs-9). However this only covers Browserbase-run browser sessions, not other data flows like server-side act/observe/extract caching (stagehand-docs-6) or local user-data directories (stagehand-docs-7), and there is no independent/hands-on confirmation of residency guarantees. Missing for 10: region control over cached LLM/action results and other stored artifacts, explicit compliance/residency guarantees, and third-party verification.
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
- [claimed-docs] “Stagehand caches `act()`, `observe()`, and `extract()` results server-side to reduce LLM costs and speed up your automations.”
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
Smoothnone0/10No evidence of data residency/region selection options; only Zero Data Retention (deletion) is mentioned, which is a different capability. Missing for 10: any mention of region choice, data center locations, or residency controls.
- [claimed-docs] “Zero Data Retention is an enterprise feature that provides enhanced data privacy by allowing you to delete all data associated with complete…”
ai-native userPrevent my data from being used to train AI models
weight 3 · round to SmoothStagehandnone0/10The axis applies to this product kind (peer products hold positive or none verdicts on this story), so lack of evidence for an applicable capability is "none", never "na". (na/none harmonized at arena bring-up — see pipeline/scripts/na-harmonize.ts.)
Smooth documents a 'Zero Data Retention' enterprise feature that lets customers delete all data tied to completed tasks, which is adjacent to preventing data reuse, but there is no explicit statement that data is excluded from model training, and this feature is gated to enterprise tier. Community feedback also notes an absence of any detailed security/privacy documentation despite marketing claims of 'enterprise-grade security', raising trust concerns without disputing the ZDR feature itself. missing for 10: explicit AI-training opt-out policy, default (non-enterprise) privacy guarantees, independent verification of data handling.
- [claimed-docs] “Zero Data Retention is an enterprise feature that provides enhanced data privacy by allowing you to delete all data associated with complete…”
- [community] “My first question was whether I could use this for sensitive tasks, given that it's not running on our machines. And after poking around for…”
ai-native userControl data retention and deletion
weight 2 · round to SmoothStagehandnone0/10Docs describe persisting user data (cookies/local storage, Browserbase contexts) and choosing a data region for jurisdiction, but there is no evidence of any deletion controls, retention limits, or user-facing settings to purge stored session/browser data. missing for 10: explicit retention policy, deletion/purge mechanism, and user controls over how long session data or extracted data is kept.
- [claimed-docs] “Stagehand creates the directory if it does not exist and leaves it in place after the browser shuts down, so the next run starts from the sa…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
Docs confirm a 'Zero Data Retention' feature letting customers delete all data tied to completed tasks, directly addressing retention/deletion control, but it's explicitly gated as an 'enterprise feature' rather than a universal capability, and no detail is given on default retention periods, deletion APIs/CLI commands, or granular controls for non-enterprise users. Community feedback (e.g., concerns about sending data to a third party, no security details found) shows some skepticism but doesn't concretely contradict the ZDR claim itself. missing for 10: default/non-enterprise retention policy, self-serve deletion mechanism (API/CLI), independent verification of ZDR working in practice.
- [claimed-docs] “Zero Data Retention is an enterprise feature that provides enhanced data privacy by allowing you to delete all data associated with complete…”
- [community] “My first question was whether I could use this for sensitive tasks, given that it's not running on our machines. And after poking around for…”
ai-native userOpt out of telemetry and usage tracking
weight 2 · round drawnStagehandnone0/10No evidence pack item discusses telemetry, usage tracking, or opt-out settings for Stagehand; documentation covers automation features, caching, and Browserbase infrastructure but is silent on telemetry practices.
Smoothnone0/10No evidence describes a telemetry/usage-tracking opt-out control; the only related privacy feature is 'Zero Data Retention' for enterprise customers, which addresses data deletion after tasks rather than disabling telemetry/tracking. Community comments raise general privacy/security concerns but do not confirm or deny an opt-out mechanism.
- [claimed-docs] “Zero Data Retention is an enterprise feature that provides enhanced data privacy by allowing you to delete all data associated with complete…”
- [community] “My first question was whether I could use this for sensitive tasks, given that it's not running on our machines. And after poking around for…”
Replay debugging — stories about replay debugging in this arenaReplay debugging
Stories about replay debugging in this arena
Live
automation-engineerWatch a session live and take human control mid-run when the agent gets stuck
weight 2 · round drawnStagehand's docs mention Browserbase's session dashboard offering real-time browser screen recording and replay, which covers 'watching a session live,' but there is no evidence of a mechanism to hand control back to a human mid-run when the agent stalls. missing for 10: explicit live take-over/human-in-the-loop control feature, evidence of pausing agent execution for manual intervention, and independent confirmation of this workflow.
- [claimed-docs] “Browserbase provides real-time visibility into your automation sessions: **Session dashboard features** * Real-time browser screen recordi…”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
Docs confirm a live_url to watch agent actions in real time (smooth-docs-2), satisfying the 'watch a session live' half of the story, but there is no evidence of any mechanism for a human to intervene or take control mid-run when the agent gets stuck. missing for 10: documented human-takeover/control API or UI, evidence of pausing/resuming agent execution, hands-on confirmation of mid-run intervention.
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
Replay
automation-engineerDebug a failed agent run from recorded replays — video, screenshots, step-by-step action timelines
weight 2 · round to StagehandStagehand relies on Browserbase's session dashboard for real-time screen recording and replay, giving some visibility into runs, but there is no documented step-by-step action timeline correlated with agent decisions, no screenshot-per-step artifact, and no dedicated debugging/replay tooling built into Stagehand itself. missing for 10: native step-by-step action timeline tied to LLM decisions, per-step screenshots, first-party replay/debug UI (beyond Browserbase's generic session recording), independent hands-on confirmation of replay-based debugging workflows.
- [claimed-docs] “Browserbase provides real-time visibility into your automation sessions: **Session dashboard features** * Real-time browser screen recordi…”
Docs mention a `live_url` for viewing agent actions live during a run, but there is no evidence of persisted video recordings, screenshots, or a step-by-step action timeline that can be replayed after a run has finished and failed. Missing for 10: recorded video/screenshot artifacts, post-hoc replay viewer, structured action timeline, and any independent confirmation of replay-based debugging.
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
Scale parallelism — running many jobs at once — concurrency, fleets, queueingScale parallelism
Running many jobs at once — concurrency, fleets, queueing
Fleets
automation-engineerRun a fleet of concurrent browser sessions with documented concurrency limits and programmatic session management
weight 2 · round drawnStagehandnone0/10The evidence shows Stagehand/Browserbase supports single-session configuration (regions, contexts, persistence, observability) but nowhere documents fleet-level concurrency limits or APIs for managing many concurrent sessions programmatically. Missing for 10: documented concurrency caps, fleet/session-pool management API, and any evidence of running many sessions in parallel.
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
- [claimed-docs] “Browserbase provides real-time visibility into your automation sessions: **Session dashboard features** * Real-time browser screen recordi…”
- [claimed-docs] “For Browserbase sessions, use contexts to persist browser data”
Smoothnone0/10The evidence pack covers single-session features (persistent sessions, live URL, proxies, structured output) but contains no documentation of concurrency limits, fleet/pool management, or APIs for running many sessions in parallel. Missing for 10: documented concurrency limits, fleet/pool orchestration APIs, rate-limit or scaling guidance, evidence of parallel session usage.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Log in once, then reuse that authentication for future tasks.”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
Lifecycle
developerGet webhook notifications when tasks and sessions finish instead of polling for status
weight 1 · round drawnStagehandnone0/10No evidence of any webhook/callback mechanism for task or session completion; Stagehand's docs focus on act/observe/extract, caching, and session dashboards but nothing about push notifications replacing polling.
Stealth captcha — stories about stealth captcha in this arenaStealth captcha
Stories about stealth captcha in this arena
Captcha
automation-engineerRely on a documented captcha stance — automatic solving, human fallback, or explicit non-support — instead of silent task failures
weight 2 · round to SmoothOnly a single community anecdote claims Stagehand/Browserbase have 'built in proxies and captcha' handling, but no first-party documentation in the pack states an explicit captcha policy (auto-solve, human fallback, or non-support). missing for 10: official docs describing captcha handling behavior, guidance on fallback/human-in-the-loop when captchas are hit, and independent verification beyond one forum comment.
- [community] “I've been playing around with Stagehand for a minute now, actually a useful abstraction here. We build scrapers for websites that are pretty…”
- [community] “I recently tried to implement a workflow automation using similar frameworks that were playwright or puppeteer based... What stopped me enti…”
Smooth explicitly documents an automatic captcha-solving stance ('Auto-CAPTCHA solvers: Bypass CAPTCHA challenges automatically, allowing for uninterrupted task execution'), giving automation engineers a clear documented behavior rather than silent failure. Community reaction (smooth-comm-3) criticizes the ethics/marketing of this feature but does not present a hands-on failure showing the solver doesn't work, so this remains a documented claim rather than a disputed one. Missing for 10: independent/hands-on verification that auto-solving actually succeeds in practice, and no documentation of fallback behavior (e.g., what happens if a captcha can't be auto-solved).
- [claimed-docs] “Auto-CAPTCHA solvers: Bypass CAPTCHA challenges automatically, allowing for uninterrupted task execution.”
- [community] “So you're shamelessly selling spambots? The marketing here is wild... "proxy rotation"... "auto-CAPTCHA solvers"”
Posture
automation-engineerPoint to the vendor's published acceptable-use and anti-abuse posture governing what its stealth and automation features may be used for
weight 1 · round drawnStagehandnone0/10No evidence pack item references a published acceptable-use policy, anti-abuse terms, or governance statement about how Stagehand's automation/anti-detection features may or may not be used; docs focus entirely on features (act/observe/extract, caching, proxies) with no mention of usage policy or abuse prevention stance.
Smoothnone0/10No evidence anywhere in the pack of a published acceptable-use policy, anti-abuse terms, or guidance on permissible use of the stealth/CAPTCHA-bypass and automation features; docs only describe how to use auto-CAPTCHA and proxy features, not what usage is disallowed. Community commentary even calls out the lack of any such framing (e.g., accusing the marketing of enabling spambots), reinforcing the absence rather than disputing a claim.
- [claimed-docs] “Auto-CAPTCHA solvers: Bypass CAPTCHA challenges automatically, allowing for uninterrupted task execution.”
- [community] “So you're shamelessly selling spambots? The marketing here is wild... "proxy rotation"... "auto-CAPTCHA solvers"”
Stealth
automation-engineerEnable stealth fingerprinting and residential or geo-targeted proxies so legitimate automations aren't blocked as bots
weight 2 · round drawnA community hands-on comment praises Stagehand/Browserbase's 'built in proxies and captcha' handling for adversarial sites, and docs confirm Browserbase supports multi-region session placement (geo-targeting) — but there is no first-party documentation of stealth fingerprinting configuration or explicit residential-proxy selection controls. missing for 10: dedicated docs on fingerprint spoofing/stealth mode, explicit residential proxy configuration options, and independent verification that bot-block evasion works reliably.
- [community] “I've been playing around with Stagehand for a minute now, actually a useful abstraction here. We build scrapers for websites that are pretty…”
- [community] “I recently tried to implement a workflow automation using similar frameworks that were playwright or puppeteer based... What stopped me enti…”
- [claimed-docs] “Browserbase runs browsers in four regions, so you can cut latency by starting the browser near your users or your target site, and keep sess…”
Docs confirm auto-CAPTCHA solving and configurable proxy server parameters plus persistent authenticated sessions, which support anti-bot automation goals, but there is no explicit mention of residential/geo-targeted proxy pools or stealth browser fingerprinting techniques. Missing for 10: explicit residential/geo-targeted proxy options, stealth fingerprinting details, and independent verification that bot-detection evasion actually works in practice.
- [claimed-docs] “To use a proxy with Smooth, you need to specify the proxy server details in your task parameters.”
- [claimed-docs] “Auto-CAPTCHA solvers: Bypass CAPTCHA challenges automatically, allowing for uninterrupted task execution.”
- [claimed-docs] “Log in once, then reuse that authentication for future tasks.”
- [community] “So you're shamelessly selling spambots? The marketing here is wild... "proxy rotation"... "auto-CAPTCHA solvers"”
Structured extraction — stories about structured extraction in this arenaStructured extraction
Stories about structured extraction in this arena
Extraction
developerExtract typed, schema-validated data (Zod/Pydantic-style) from pages the agent visits, not just raw text
weight 3 · round to SmoothStagehand's documented extract() API takes an instruction plus an output shape (schema), directly matching typed/schema-validated extraction rather than raw text scraping. Missing for 10: explicit mention of Zod/Pydantic naming in the evidence pack, independent/hands-on confirmation of schema validation behavior beyond docs.
- [claimed-docs] “extract() grabs structured data from a webpage. Every call takes an instruction and an output shape”
- [claimed-docs] “observe() discovers actionable elements on a page and returns structured actions you can execute or validate before acting.”
Docs explicitly describe structured outputs via `response_model` for deterministic typed data and a dedicated `session-extract` method to extract structured data from a page by providing a schema, directly matching the story. Missing for 10: explicit Zod/Pydantic code examples and independent/hands-on confirmation that extraction validation works as documented.
- [claimed-docs] “Structured outputs allow you to write deterministic code based on the agent's output. To activate structured outputs, set the `response_mode…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
Files
developerMy agent can download files from and upload files to the sites it operates, with the artifacts retrievable afterwards
weight 1 · round drawnStagehandnone0/10The evidence pack covers Stagehand's act/observe/extract primitives, session persistence, and MCP integration, but nowhere mentions file download/upload handling or artifact retrieval after a session ends. Since browser automation tools plausibly support file transfer, this is an applicable axis with no supporting evidence.
Smoothnone0/10The evidence pack describes Smooth's session workflows, structured extraction, live-view, proxies, and persistent auth, but nothing addresses file download/upload during a browser session or persisting artifacts for later retrieval. Since browser automation tools plausibly support file transfer (e.g., downloading a report from a site or uploading a document to a form), this axis applies but is unaddressed.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
- [claimed-docs] “When running a task, you will receive a `live_url`, which can be used to view the agent actions live.”
Not comparable on these axes
ai-native userSubscribe to events via webhooks
weight 2 · not comparableStagehandn/aStagehand is a browser automation SDK for agents/scripts to control web pages, not an event-driven platform; no evidence of any webhook subscription mechanism, and this is a category error for the product type rather than a missing feature.
ai-native userGet AI-generated insights and suggestions from my data inside the product
weight 2 · not comparableStagehandn/aStagehand is a browser-automation/data-extraction library (act/observe/extract on web pages), not a product that stores 'my data' and surfaces AI-generated insights/dashboards from it — this consumer-analytics axis doesn't apply to its category.
Smoothn/aSmooth is a browser-automation SDK/CLI that lets AI agents navigate the web and extract structured data from pages — it is not a data platform or analytics product with a UI that surfaces AI-generated insights/suggestions from a user's own data. This story targets a different product category (BI/analytics-style in-product insights), so it does not apply to Smooth's browser-agent tooling.
- [github] “The Smooth CLI is a browser for AI agents, enabling tools like Claude Code to navigate the web quickly, cheaply, and reliably.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Extract structured data from the current page by providing a schema.”
ai-native userDefine rules that trigger actions automatically on events
weight 3 · not comparableStagehandnone0/10The evidence describes Stagehand's act/observe/extract primitives for executing AI-driven browser actions, caching, and self-healing selectors, but nothing about defining persistent rules that automatically trigger on events (e.g., webhooks, schedules, DOM-change listeners) outside of an explicit script invocation.
Smoothn/aSmooth is a browser-automation/agent-tool product for running tasks on demand, not an event-driven rules/automation-trigger platform; there is no mention of defining rules or triggers that fire actions on events, so this automation-depth axis (workflow/event triggers) is a category mismatch for this product type.
ai-native userSchedule recurring jobs or workflows
weight 2 · not comparableStagehandn/aStagehand is a browser-automation SDK/library for scripting and controlling browser sessions via natural language, not a scheduling/orchestration platform; the evidence pack contains no concept of cron-like recurring job scheduling, and this capability is outside the product's category (scheduling would be handled by an external orchestrator invoking Stagehand scripts).
Smoothnone0/10No evidence of scheduling, cron-like triggers, or recurring workflow orchestration; Smooth is documented as a task-execution/browser-automation tool (session workflows, extraction, structured output) with no mention of recurring/scheduled jobs. Missing for 10: any scheduling API, cron/trigger mechanism, or recurring workflow docs.
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
ai-native userVersion, review, and roll back my automations
weight 1 · not comparableStagehandn/aStagehand is a browser automation library/SDK, not a workflow/automation builder with saved automation artifacts; versioning, review, and rollback of 'automations' is not a fair axis for a code-driven browser scripting tool — this is a category error, not a missing feature.
Smoothn/aSmooth is a browser-automation/AI-agent-browsing tool (task execution, sessions, structured extraction) rather than an automation-authoring platform with version history or workflow rollback semantics; versioning/review/rollback of 'automations' is not an applicable axis for this product category.
ai-native userDo everything through the API that I can do in the UI
weight 2 · not comparableStagehandn/aStagehand is fundamentally a code-first SDK/API for browser automation (act/observe/extract calls, MCP integration); it has no separate primary UI whose feature set the API would need to match, aside from the auxiliary Browserbase session dashboard which is a different product's observability layer. The API-vs-UI parity framing is a category error for this kind of dev tool.
Smoothnone0/10The evidence pack shows Smooth as an API/CLI/SDK-first browser-automation tool with docs for tasks, sessions, proxies, custom tools, and a live_url for viewing agent actions, but there is no mention of a separate web dashboard/UI or any comparison of UI-only vs API-only capabilities. Without evidence of what a UI offers (or that all UI features are mirrored in the API), the parity claim can't be substantiated. Missing for 10: any documented web UI/dashboard, and an explicit statement or demonstration that all UI actions are also achievable via API.
- [claimed-docs] “Plug-and-play: Run a task in just 4 lines of code, making it easy to integrate into your workflow.”
- [claimed-docs] “Session Workflow — Multi-step execution where you can orchestrate smaller tasks, navigate to URLs, and extract data within a persistent brow…”
- [probe] “official CLI documented at https://docs.smooth.sh/cli/overview”