Open-source AI agent for the web

Describe the task, Nanobrowser does the work.

Add to Chrome Add to Edge

Find the three tallest mountains in Europe, make a table of their heights, and save them into a new Google spreadsheet

Let me read the peaks section for heights.

Got the data: Elbrus 5,642 m, Dykh-Tau 5,205 m, Shkhara 5,193 m. Next I'll create the spreadsheet.

I made a new Google spreadsheet called "Tallest Mountains in Europe" with the three tallest mountains in Europe.

RankMountainmft

1Mount Elbrus5,64218,510

2Dykh-Tau5,20517,077

3Shkhara5,19317,037

CopySave as CSV

No model lock-in

Use the AI model you like: OpenAI, Anthropic, Gemini, DeepSeek, OpenRouter, or a model on your own computer.

OpenAI
Anthropic
Gemini
DeepSeek
OpenRouter
Local models

Runs in your logged-in browser

It works locally in the browser you already use, with the sites and accounts you're signed into.

Free and open source

No sign-up, no subscription. Apache-2.0 on GitHub. Your API keys and chats are kept in your browser.

★ Star on GitHub · 14.1k Join Discord

FAQ

What is Nanobrowser?

An open-source AI agent for the web. It runs as a Chrome and Edge extension in the browser's side panel and works in your real, signed-in browser: tell it what you need and it clicks, types and reads pages to get it done.

Which AI models can I use?

Anthropic, OpenAI, Google Gemini, OpenRouter, xAI Grok, DeepSeek, Mistral, any service that works like OpenAI's, or a model on your own computer. Add one in Settings → Providers, paste your API key (a local model needs none) and pick a model.

Is it free?

Yes. Nanobrowser is free and open source, with no sign-up. You pay your model provider directly for what you use.

Where do my API keys and chats go?

Your keys and chats are stored in your browser. Each key goes only to its own provider. Your messages and the pages the agent reads go to the model provider you pick. No Nanobrowser server sees them.

Will it act without asking me?

In Ask mode, the default, it asks before it submits, sends, deletes or uploads anything. You can allow it once, allow it on that site, or deny it. It may not spot every such step, so keep an eye on it.

How can I contribute?

Open issues and pull requests on GitHub, or share prompts and feedback in Discord.