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Steel

Open-source browser infrastructure for AI agents at scale

open sourceupdated Aug 16, 2026

Steel is an open-source browser API purpose-built for AI agents, providing managed headless browser sessions with anti-bot bypass, proxy rotation, CAPTCHA solving, and session persistence. It handles the infrastructure layer that browser automation agents like Browser Use and Stagehand run on top of. Self-hostable or available as a cloud service. Over 6,000 GitHub stars.

Steel addresses the infrastructure gap between browser automation frameworks and production-scale AI agent deployments. Tools like Browser Use, Stagehand, and Playwright provide the orchestration logic for navigating websites, but running reliable browser sessions at scale requires solving a different set of problems: anti-bot detection, IP rotation, CAPTCHA handling, session persistence across page navigations, and resource management for concurrent browser instances. Steel packages these infrastructure concerns into a clean API that automation frameworks can connect to, separating the what (agent logic) from the how (browser infrastructure).

The platform exposes browser sessions through a RESTful API with WebSocket streaming for real-time interaction. Each session runs in an isolated browser context with configurable stealth headers, rotating residential proxies, and automatic CAPTCHA solving. Sessions can persist cookies and localStorage across multiple API calls, enabling workflows that require authenticated browsing like logging into dashboards or managing accounts. The session recording feature captures full interaction traces for debugging and compliance, while resource limits prevent runaway sessions from consuming excessive compute.

Steel grew 50x through 2025 as AI agent adoption accelerated and developers discovered that reliable browser infrastructure was the bottleneck for production deployments. The open-source core under Apache-2.0 can be self-hosted via Docker for teams that need data sovereignty, while the managed Steel.dev cloud handles scaling and proxy management for usage-based pricing. With over 6,000 GitHub stars and integration partnerships with major browser automation frameworks, Steel has carved out the browser infrastructure as a service niche within the AI agent ecosystem.

Pricing

Free self-hosted (Apache-2.0); Steel.dev cloud usage-based

Platforms

Docker self-hosted or Steel.dev cloud API

Categories

Tags

Use Cases

Browser Use logo

Browser Use

AI agent framework for web browser automation

Browser Use is an open-source AI agent framework with 99K+ GitHub stars enabling LLMs to control web browsers via natural language. Y Combinator-backed, it lets agents navigate sites, fill forms, extract data, and complete multi-step tasks autonomously. Built on Playwright with vision-based element detection, multi-tab management, cookie persistence, and self-correcting actions. Supports OpenAI, Anthropic, and local models with a simple Python API for building custom browser agents.

Open Source
E2B logo

E2B

Secure cloud sandboxes for AI agents

E2B provides secure cloud sandboxes that let AI agents execute code, run terminal commands, and interact with filesystems in isolated environments. Each sandbox spins up in ~150ms with its own OS, giving agents a safe space to run untrusted code. Supports Python, JavaScript, and any language via custom Dockerfiles. Used by AI coding assistants, data analysis agents, and code interpreters. SDK available for Python and JavaScript with a simple API for programmatic sandbox control.

freemiumOpen Source
Stagehand logo

Stagehand

AI-powered web browser automation with Playwright

Stagehand is an open-source browser-agent SDK from Browserbase that combines deterministic browser automation with AI primitives such as act(), extract(), observe(), and agent(). Instead of relying only on brittle selectors, developers can use natural-language actions, Zod-backed structured extraction, page observation, action caching, and Browserbase cloud-browser infrastructure for production web automation.

Open Source
Skyvern logo

Skyvern

Browser automation with AI vision — no XPath or DOM parsing needed

Skyvern automates browser-based workflows using LLMs and computer vision instead of brittle XPath or CSS selectors. It understands web pages visually, navigating forms, clicking buttons, and extracting data like a human would. Achieved 85.85% success rate on WebVoyager benchmark and SOTA on WRITE tasks for RPA. 21,000+ GitHub stars, AGPL-3.0 licensed. Skyvern Cloud offers managed usage-based hosting for teams that prefer not to self-host the infrastructure.

Open Source
Microsandbox logo

Microsandbox

Local microVM sandboxes for AI agent code execution

Microsandbox provides hardware-level isolated sandboxes for AI agents to execute code safely on local machines. Using libkrun microVMs and a 320ms bare-metal Linux/KVM homepage benchmark, it offers stronger isolation than Docker containers while staying lightweight enough for dev workstations. OCI-compatible with Python and Node.js runtimes. Apache-2.0 licensed with 6.6K+ GitHub stars.

Open Source
Tabstack logo

Tabstack

Mozilla-backed browser infrastructure for AI agents

Tabstack is Mozilla's browser infrastructure service for AI agents, providing clean markdown extraction, structured JSON data, and automated browser actions through a fast API. With two-tier fetch escalation that achieves sub-600ms latency for static pages, robots.txt compliance, and ephemeral data handling, it offers an ethical alternative to aggressive web scraping tools — complete with an MCP server for Claude and Cursor integration.

freemium

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Comparisons

Browserless vs Steel — Headless Browser Infrastructure for AI Agents

Browserless and Steel both provide headless browser infrastructure for automation and AI agent workflows. Browserless offers a mature, Docker-based platform with MCP server support and connection pooling, while Steel focuses on AI-native browser sessions with built-in anti-detection. This comparison examines which platform better serves modern AI agent automation needs.

FAQ

What is Steel?

Steel is an open-source browser API purpose-built for AI agents, providing managed headless browser sessions with anti-bot bypass, proxy rotation, CAPTCHA solving, and session persistence. It handles the infrastructure layer that browser automation agents like Browser Use and Stagehand run on top of. Self-hostable or available as a cloud service. Over 6,000 GitHub stars.

Is Steel free?

Yes — Steel is open source and free to use. Free self-hosted (Apache-2.0); Steel.dev cloud usage-based

Is Steel open source?

Yes — Steel is open source.

What are the best Steel alternatives?

The top editor-verified Steel alternatives are Browser Use, E2B, Stagehand, and more.