Webbrain

WebBrain is an open source AI browser agent for Chrome, Firefox and Edge. It is positioned as a free alternative to Claude in Chrome, and it works with any model, including local ones, so page content can stay on the user's own machine. It connects to llama.cpp, Ollama, OpenAI, Claude and OpenRouter, and the interface is available in multiple languages. The extension has Ask, Act and Dev modes. In Ask mode it summarizes the current page and answers questions about it. In Act mode it can fill out forms using remembered details, stopping before submit so the user can review, download a video from a page, or extract structured data such as product names and prices. In Dev mode it inspects a page in DevTools and suggests style and code changes. Screenshots are handled in a token conscious way to keep model costs down. A newly announced MCP server lets Claude Code, Codex and Cursor drive the browser through WebBrain. The code is licensed under GPL 3.0 or later. The extension is listed on the Chrome Web Store and the source is on GitHub. WebBrain is free. The site's comparison table lists the price as free forever, against Claude in Chrome, which it notes requires a Claude Pro subscription at $20 per month. Costs for hosted models such as OpenAI or Claude are billed separately by those providers, while local models carry no per request charge.