WebBrain: open-source local-first AI browser agent for Chrome and Firefox
A browser extension that puts an AI agent in a side panel to chat with pages, click/type/navigate through tasks, and run multi-step workflows on your choice of LLM, including fully local models.
Why it matters
Ask/Act/Dev modes with per-site permission prompts, 112 provider cards, local-model support and an MCP server: the most mature open-source browser agent, now surging on GitHub trending.
What you could build with it
A market-research freelancer could run WebBrain on a local Ollama model in Act mode with /watch to poll a competitor's pricing page and flag changes, automating competitive monitoring without sending page data to any cloud.
Does it hold up?
Real product: 227 releases, 6,107 commits, on Chrome/Firefox/Edge stores, per-site permission prompts and plan-before-act approvals; the local-model path works, though complex JS-heavy pages remain a challenge per reviewers.
Built with WebBrain
- Meet WebBrain: An Open-Source, Local-First AI Browser AgentMarkTechPost · In-depth review: local and cloud provider setup, recommended Qwen 3.6 35B model, and pricing of the $5/month managed WebBrain Cloud.
- I built an open-source browser agent that runs on your local LLMDEV Community · Builder's writeup: three explicit modes, local-first philosophy, and a new MCP bridge into Claude Code.
Learn more
First spotted on github: source.
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