BlogProjectsAbout MeResume

Browser AI Chat

AI chat application that runs entirely in the browser using local models like Gemini Nano, Transformers.js, and WebLLM for private, serverless AI.

Demo GitHub
reacttypescriptviteaipwa
Open demo in new tab

About

An AI chat application that runs entirely in the browser — no server, no API keys, no data leaving your device. It supports multiple local AI backends:

  • Gemini Nano via Chrome’s built-in AI APIs
  • Transformers.js for running Hugging Face models in-browser
  • WebLLM for larger models via WebGPU

Why I built this

I wanted to explore what’s possible with client-side AI in 2025+. As browser capabilities improve (WebGPU, built-in AI APIs), more AI workloads can run locally without sacrificing too much quality. This project is a testbed for those possibilities.

What I owned

  • Designed the full client-only app architecture
  • Integrated multiple local AI runtimes behind one chat experience
  • Built local persistence for conversation history and attachments
  • Shipped the project as an installable PWA without backend infrastructure

Technical highlights

  • Zero backend — everything runs in the browser
  • WebGPU acceleration where available
  • Conversation history stored locally
  • Model switching between different AI backends
  • No servers, no API keys, no data collection

Features

  • Local AI Models: Built-in AI (Gemini Nano), Transformers.js, WebLLM
  • Complete Privacy: All processing happens in your browser
  • Multi-modal: Text, images, documents, audio
  • Offline: Works without internet after setup
  • PWA: Install like a native app
  • File Support: Drag-and-drop attachments

Tech Stack

  • React + TypeScript + TailwindCSS
  • Vite + PWA
  • TanStack Router
  • IndexedDB (Dexie)

What this shows

This project shows the kind of AI product engineering I enjoy: understanding new platform capabilities, designing a practical abstraction around messy runtime differences, and shipping a product that users can try directly.

Development

Terminal window
git clone https://github.com/bimsina/browser-chat.git
pnpm install
pnpm dev

Model Types

Built-in AI: Browser native (Chrome/Edge only), instant startup

Transformers.js: ONNX models, good variety, medium size

WebLLM: Large models, most capable, bigger downloads

Browser Support

  • Chrome/Edge: Full support
  • Firefox: Transformers.js + WebLLM
  • Safari: Transformers.js only