Visit https://metadata.nostr.com or https://follows.nostr.com. To restore your contacts, you’ll need a browser extension:

- For Desktop: Use Nostr Connect on Chrome browsers that support extensions.

- For Android: Use Kiwi Browser with Nostr Connect.

- For iOS: Use the Nostore app extension for Safari.

2. Using Nostur (iOS)

The Nostur app notifies you when it detects a new version of your contact list and offers options to restore or approve changes.

- Important: You must already be a Nostur user before losing your contact list.

- Download Nostur: https://apps.apple.com/us/app/nostur-nostr-client/id1672780508

3. Using Citrine (Android)

The Citrine relay runs locally on your phone, enabling contact restoration from a backup.

- Important: Citrine must be set up before your contacts are lost.

- Learn more: https://github.com/greenart7c3/Citrine or nostr:npub10r8xl2njyepcw2zwv3a6dyufj4e4ajx86hz6v4ehu4gnpupxxp7stjt2p8.

4. Using Primal Premium

If you’re a Primal Premium user, go to the Nostr Tools section and select "Contacts Backup." You can view all backups and choose a restore point.

- More info: https://primal.net/premium

Good luck!