Enable Real-time Collaboration

To sync boards between users in real time you need a free Firebase Realtime Database. It takes about 5 minutes to set up and requires no credit card.

1. Go to console.firebase.google.com and create a project.
2. Click Add app → Web, register the app, and copy the firebaseConfig object.
3. In the left menu go to Build → Realtime Database → Create database → Start in test mode.
4. Paste the config JSON below and click Save & Connect.

Config is stored in localStorage — you only need to do this once per browser. Without Firebase the board is saved locally and sharing a link won't sync data.