BrainBox — AI in your browser

No install · No server · No cloud

AI that lives inside your browser.

A real language model — downloaded once, cached on your device, and run entirely on your machine. No WebGPU required. Falls back to high-performance WASM on any modern browser. Nothing leaves your computer.

100% Private

Works offline

No signup

No API key

Free forever

Choose your mind

Each model downloads once and is cached on your device. Future launches are instant.

Web boost (Wikipedia)

Initializing… 0%

Cached models load instantly · runs locally · zero data leaves your device

What's on your mind?

Your model is loaded and running locally. Type anything — every token is generated on your device.

Tell me a surprising fact about the ocean

Write an email to my future self

Explain transformers like I'm 12

Side-project ideas for a designer

Running locally · all data stays on your device ↵ send · ⇧↵ newline