Browse the web together in real-time.

Not screen sharing. Not a video call overlay. The actual browsing experience, synchronized between participants.

Website: https://b.krl.kr
GitHub: https://github.com/3289david/shared-browser

• Live cursors - see everyone's cursor position on the page, labeled with names
• Synchronized navigation - follow a leader or browse as a group
• Annotations - highlights, sticky notes, and drawings visible to all
• Real-time chat - sidebar chat without leaving the browser
• Shared history - full timeline of every page visited in the session
• Split & Merge - break off independently, merge back with one click
• Session recording - events, not video. Tiny file size, full replay

shared-browser/
├── extension/          Chrome/Firefox extension (WebExtension API)
│   ├── manifest.json   Chrome Manifest V3
│   ├── manifest-firefox.json  Firefox Manifest V2
│   ├── background.js   Service worker
│   ├── content.js      Page injection (cursors, annotations, sidebar)
│   ├── popup.html/js   Extension popup
│   ├── sidebar.html/js Sidebar panel
│   └── icons/          Extension icons
├── server/             Node.js real-time server
│   └── src/index.js    Socket.io server
└── docs/               Landing page (GitHub Pages)
    ├── index.html
    ├── css/style.css
    └── js/main.js

cd server
npm install
cp .env.example .env
npm start

Runs on port 3001 by default. Deploy this to your server and update the SERVER_WS URL in extension/content.js and extension/background.js.

1. Open Chrome and go to chrome://extensions
2. Enable "Developer mode"
3. Click "Load unpacked"
4. Select the extension/ folder

1. Open Firefox and go to about:debugging
2. Click "This Firefox" > "Load Temporary Add-on"
3. Select extension/manifest-firefox.json

The WebSocket server URL is set in extension/content.js:

const SERVER_WS = 'wss://api.b.krl.kr';

Change this to your deployed server URL before building for production.

Any Node.js host works: Railway, Fly.io, DigitalOcean, etc.

cd server
npm install --production
PORT=3001 node src/index.js

The docs/ folder is configured for GitHub Pages. Enable GitHub Pages in repository settings, set source to docs/ folder.

MIT