Rosseta

A browser extension that translates text from any region of a webpage. Select an area on screen, and the extension captures, extracts, and translates the text using AI — all without leaving the page.

Named after the Rosetta Stone — the ancient artifact that unlocked the mystery of Egyptian hieroglyphs. Just as the stone bridged languages carved in stone, Rosseta bridges languages rendered on screen.

Successor of select-and-translate — rebuilt from scratch with a proper architecture.

Built with Svelte 5, TypeScript, Tailwind CSS v4, and a DDD + Hexagonal architecture.

Demo

Features

• 🖱️ Region select — Draw a box on any part of a page, including images, and get an instant translation overlay with romanization
• 🤖 Multi-provider — Switch between Gemini and Groq models on the fly
• 🌍 110+ languages — Gemini supports 110 languages, Groq (Llama 4) supports 12 — auto-filtered per provider
• 🔑 Key management — Multiple API keys per provider with auto-rotation
• 🌐 Proxy support — Route all API calls through your own relay server
• 📜 History — Every translation saved locally, searchable
• 🌙 Dark mode — System-aware with manual toggle

Install

• Chrome — Install from Chrome Web Store
• Firefox — Install from Firefox Add-ons

Contributing

See CONTRIBUTING.md for setup instructions, architecture details, coding standards, and the pull request process.

Proxy Setup (Optional)

Rosseta can route all API requests through a proxy server instead of calling the AI provider directly.

Why use a proxy?

• Your network blocks generativelanguage.googleapis.com or api.groq.com
• You want to hide your IP address from the API provider
• You need request logging, rate limiting, or caching on your own server

How it works

The proxy URL replaces the base URL of the API. Rosseta appends the original path and query string to your proxy URL:

Important: Your API key is still included in the request (as a query param for Gemini, as an Authorization header for Groq). Make sure you trust your proxy server.

Configuration

1. Open the extension popup → ☰ menu → Proxy Settings
2. Enter your proxy server URL
3. Click Save — a health check runs automatically
4. ✅ Connected = proxy is working, ✗ Unhealthy = proxy is unreachable (not saved)

To go back to direct connections, click Clear.

Example: Cloudflare Worker

A minimal reverse proxy that forwards requests to the original API:

// The path after your worker URL is the AI provider's path.
// Your proxy URL should be set to: https://your-worker.workers.dev/v1beta/models
// (for Gemini) or https://your-worker.workers.dev/openai/v1 (for Groq).

const PROVIDERS = {
  '/v1beta/': 'https://generativelanguage.googleapis.com',
  '/openai/': 'https://api.groq.com',
};

export default {
  async fetch(request) {
    const url = new URL(request.url);

    // Determine target based on path prefix
    let target;
    for (const [prefix, origin] of Object.entries(PROVIDERS)) {
      if (url.pathname.startsWith(prefix)) {
        target = origin;
        break;
      }
    }

    if (!target) {
      return new Response('Unknown provider path', { status: 400 });
    }

    return fetch(target + url.pathname + url.search, {
      method: request.method,
      headers: request.headers,
      body: request.body,
    });
  },
};

With this worker deployed at https://your-worker.workers.dev, set your proxy URL to https://your-worker.workers.dev/v1beta/models for Gemini or https://your-worker.workers.dev/openai/v1 for Groq.

Tip: Since both providers use different base URLs, you'll only be proxying whichever provider you configure. To proxy both, you'll need one proxy URL per provider — or a single proxy that inspects the path to determine the target (like the example above).

Roadmap

• Release to Chrome Web Store and Firefox Add-ons
• Add OpenRouter provider
• Add proxy support
• Improve UI/UX

Privacy

Rosseta does not collect, store, or transmit any personal data to our servers.

• API keys, preferences, and translation history are stored locally in your browser using browser.storage.local and never leave your device.
• Translation requests (screenshots of selected areas) are sent directly from your browser to the AI provider you configured (Google Gemini or Groq) using your own API key. We have no access to this data.
• No analytics, tracking, or telemetry of any kind.

License

This project is licensed under the MIT License.