Open Source · Free Forever

The Open-Source AI Browser Agent

WebBrain is a free, open-source browser extension that brings AI agent capabilities to Chrome and Firefox. Read pages, extract data, and automate web tasks — powered by your choice of LLM. The self-hostable alternative to proprietary browser AI plugins.

Install Extension View on GitHub
https://example.com/products

Product Catalog

🧠 WebBrain
Extract all product names and prices from this page
Reading page
Extracting data
Found 24 products. Here are the results:
1. Widget Pro — $29.99
2. Super Gadget — $49.99
3. MegaTool X — $19.99
...and 21 more
Ask anything about this page...
Features

Everything you need in a browser AI

A full-featured AI agent that lives in your browser sidebar and understands any web page.

📖

Page Understanding

Reads and comprehends any web page — articles, docs, dashboards, forms. Ask questions and get instant answers from the current page content.

🤖

Full Browser Agent

Click, type, scroll, navigate, and interact with pages on your behalf. Automate repetitive tasks with natural language instructions.

📊

Data Extraction

Extract structured data from any page — tables, lists, links, forms. Export product catalogs, search results, or any page content.

🔌

Multi-Provider LLM

Works with local llama.cpp, OpenAI, Anthropic Claude, and OpenRouter. Use your preferred model — or run completely offline with local AI.

🛡️

Privacy First

Your data stays yours. Run with a local LLM for zero data leakage. No telemetry, no tracking, no accounts required. Fully open-source.

Smart Context

Automatic context management prevents token overflow. Intelligently trims conversation history and limits tool output for smooth, uninterrupted sessions.

LLM Providers

Bring your own AI

Connect to any OpenAI-compatible API or run a local model. Switch providers anytime from the extension settings.

🦙
llama.cpp (Local)
OpenAI
Anthropic Claude
OpenRouter
Interaction Modes

Ask or Act

Two modes for different needs. Read-only by default, full agent power when you need it.

💬

Ask Mode

Read-only. Ask questions about the current page, extract information, summarize content. Safe and non-intrusive — nothing gets modified.

Act Mode

Full agent. Click buttons, fill forms, navigate between pages, run scripts. Automate complex multi-step browser workflows with a single instruction.

Get Started

Install WebBrain

Available for Chrome and Firefox. Free, open-source, no account required.

🌐

Chrome

Manifest V3 · Chrome 116+

Download for Chrome
🦊

Firefox

Manifest V2 · Firefox 109+

Download for Firefox
Why WebBrain?

How does WebBrain compare?

WebBrain sits at the intersection of browser-native AI plugins and full agent frameworks. Here's how it stacks up.

vs. Browser AI Plugins

Feature WebBrain Claude in Chrome
Open SourceMIT LicenseProprietary
PriceFree foreverRequires Claude Pro ($20/mo)
Local LLM supportllama.cpp, OllamaNo — Claude only
Multi-provider4 providers (local + cloud)Claude only
ChromeYes (MV3)Yes
FirefoxYes (MV2)No
Side panel UIYesYes
Ask / Act modesYesSimilar
Fully offlineYes (with local LLM)No — cloud required
Page interactionContent scriptChrome DevTools Protocol
Self-hostableYesNo

vs. AI Agent Frameworks (different category)

Aspect WebBrain OpenClaw / Browser-Use / etc.
What is it?Browser extension (end-user tool)Agent framework / SDK (developer tool)
Target userAnyone — no coding neededDevelopers building automations
InstallationOne-click browser installPython/Docker setup required
UIBuilt-in side panel chatNo UI — code or API only
Browser controlContent script (lightweight)CDP / Playwright (full control)
Multi-tab workflowsPer-tab conversationsProgrammable multi-tab orchestration
Headless modeNo — runs in your browserYes — headless automation
ExtensibilityAdd custom LLM providersFull Python SDK, custom tools
Best forDaily browsing AI assistantAutomated scraping / testing pipelines

WebBrain is a browser extension for end users who want an AI assistant while they browse. Agent frameworks like OpenClaw are developer tools for building automated browser pipelines. Different tools for different jobs — and you can use both.

FAQ

Frequently Asked Questions

Is WebBrain a free alternative to Claude's browser plugin?

Yes. WebBrain provides similar AI browser agent capabilities — reading pages, extracting data, clicking buttons, filling forms, and automating multi-step workflows. Unlike Claude's proprietary browser plugin which requires a Claude Pro subscription and only works with Anthropic's models, WebBrain is completely free, open-source (MIT license), and supports multiple LLM providers including local models that run entirely on your machine.

How does WebBrain compare to OpenClaw, Browser-Use, and other AI agent frameworks?

They're different categories of tools. WebBrain is a browser extension — you install it in Chrome or Firefox and chat with it in a side panel, no coding required. Frameworks like OpenClaw and Browser-Use are developer SDKs for building automated browser pipelines in Python, typically using headless browsers and CDP. Think of it this way: WebBrain is for daily browsing with an AI assistant; agent frameworks are for building scraping bots and test automation. You can use both — they complement each other.

Can I use WebBrain completely offline?

Yes. WebBrain's default provider is llama.cpp, which runs a local AI model on your computer. No API keys needed, no internet required for the AI, and no data ever leaves your machine. Just download a GGUF model, start llama-server, and you have a fully private AI browser agent. You can also use Ollama with its OpenAI-compatible endpoint.

Which AI models does WebBrain support?

WebBrain supports four provider types: llama.cpp (any local GGUF model), OpenAI (GPT-4o, GPT-4, etc.), Anthropic Claude (Claude Opus, Sonnet, Haiku via native API), and OpenRouter (access to 100+ models from various providers). Any OpenAI-compatible API endpoint works, so you can also use services like Together AI, Groq, Mistral, or any local server with an OpenAI-compatible interface.

Does WebBrain work on Firefox?

Yes. WebBrain ships with both a Chrome version (Manifest V3, using the sidePanel API) and a Firefox version (Manifest V2, using sidebar_action). Both versions have identical features. The Firefox version can be loaded as a temporary add-on for development, or published to addons.mozilla.org for permanent installation.

Is WebBrain safe to use? Can it modify web pages?

WebBrain has two modes: Ask mode (default) is read-only and cannot modify anything on the page. Act mode enables full browser agent capabilities (clicking, typing, navigating) but requires explicit user confirmation before activation, and comes with a visible warning banner. You can stop the agent at any time with the Stop button. The extension's source code is fully open for audit on GitHub.

How do I use WebBrain for web scraping and data extraction?

Simply open any web page, open the WebBrain side panel, and ask in natural language: "Extract all product names and prices from this page", "Get all email addresses on this page", or "Summarize this article in bullet points". The AI agent reads the page content, understands the structure, and returns the extracted data. For more complex scraping, switch to Act mode and the agent can navigate between pages, click pagination buttons, and aggregate data across multiple pages.

Can I contribute to WebBrain?

Absolutely! WebBrain is MIT-licensed and welcomes contributions. Check out the GitHub repository for issues, feature requests, and contribution guidelines. Some planned features include CDP (Chrome DevTools Protocol) integration, file download/upload support, conversation export, and custom tool definitions.

100% Open Source

WebBrain is MIT-licensed. Inspect the code, contribute features, or fork it and make it your own.

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