Stagehand
Open-source browser automation framework that understands plain English
Overview
Stagehand is built to fix a specific frustration with tools like Playwright and Selenium: scripts break the moment a site's layout changes because they depend on exact selectors. Stagehand resolves instructions with AI at runtime instead, so an act() call like "click the login button" still works even after a redesign moves the button. It keeps deterministic control rather than handing everything off to a black-box agent, which makes it easier to debug than a fully autonomous system.
The framework itself is fully open source and free under MIT license, so you can run it entirely locally with no cost beyond your own LLM API bill. When you need production-grade reliability, session replay, or CAPTCHA solving, it connects to Browserbase's cloud browser infrastructure, which is a separate paid product starting around $20 a month. That split keeps Stagehand accessible to any developer while giving a clear upgrade path once a project moves from experiment to production.
Key Features
act(): Executes browser actions like clicking, typing, and navigating from plain-English commands.
extract(): Pulls structured data off a page with schema validation instead of manual parsing.
observe(): Identifies actionable elements on a page before committing to an action, reducing wrong clicks.
agent(): Runs multi-step workflows autonomously while keeping deterministic control over each step.
Multi-Language Support: Available in TypeScript and Python with support for OpenAI, Anthropic, and Gemini models.
Local-First: Runs against any local Chromium browser with no required cloud dependency.
Pricing
Starting price
Free and open source; optional cloud infrastructure via Browserbase starts at $20/mo
Stagehand (framework): Free and open source under MIT license. Runs locally with any Chromium browser; only LLM API usage costs apply.
Browserbase Free (optional cloud infra): $0/month. 1 browser hour included.
Browserbase Developer: $20/month. 100 browser hours.
Browserbase Startup: $99/month. 500 browser hours, 100 concurrent browsers, 5GB proxy data.
Browserbase Enterprise: Custom pricing for higher volume and dedicated support.
Disclaimer: pricing may change, confirm on Stagehand's and Browserbase's own pricing pages before buying.
Pros
Free and Open Source: The core framework costs nothing and is fully auditable on GitHub.
Resilient to Site Changes: AI-resolved actions survive layout redesigns that would break a traditional selector-based script.
Deterministic Control: Developers choose when to hand off to AI versus keep explicit control, unlike a fully autonomous agent.
Multi-Language and Multi-Model: Works in TypeScript and Python across OpenAI, Anthropic, and Gemini models.
Clear Upgrade Path: Optional Browserbase integration adds cloud browsers and session replay without switching frameworks.
Cons
Developer-Only: Requires writing code; there is no visual builder for non-technical users.
LLM Costs Add Up: Every act(), extract(), or observe() call spends tokens on your own LLM provider bill, separate from the framework itself.
Tied to Browserbase for Scale: Production-grade features like CAPTCHA solving and session replay require adopting a separate paid product.
Younger Ecosystem: Smaller community and fewer resources than long-established frameworks like Playwright or Selenium.
What Makes It Unique
AI Selectors With Deterministic Control: Stagehand blends natural-language, AI-resolved actions with explicit developer control over each step, avoiding both brittle traditional scripts and fully opaque autonomous agents.
Kay Score
7.7
/ 10
Tool Information
Pricing
Free and open source; optional cloud infrastructure via Browserbase starts at $20/mo
Category
Coding & Development
Platform
Web / iOS / Android
Last Updated
