If your library isn’t syncing across devices, here’s how to fix it step by step.

⚠️ Important: before doing anything, on the device that has the complete and up-to-date library, create a manual backup:

• Open Book Tracker > Settings > Backup & Restore > Create Backup.This ensures you won’t lose any data during the procedure.

Step 1 – Try to fix the device that is out of sync

1. On the device where the library is incomplete, open the Settings app.
2. Tap your Apple ID > iCloud.
3. Under Apps Using iCloud, tap Show All.
4. Find Book Tracker and turn it OFF.
5. Open Book Tracker: the library will clear.
6. Go back to Settings > iCloud > Show All and re-enable Book Tracker.
7. Open Book Tracker and wait for the library to download from iCloud.

If your data appears correctly, the issue is solved.

Step 2 – If the problem persists

If the out-of-sync device still doesn’t update, it usually means the device with the full library stopped uploading to iCloud.

To fix it:

1. On the device with the complete library, go to Settings > iCloud > Show All.
2. Turn Book Tracker OFF.
3. Open Book Tracker (the local library will clear).
4. Turn Book Tracker ON again.
5. Open Book Tracker and wait — the app will reconnect and start uploading the library to iCloud.

Step 3 – Restore the missing data

After this, Book Tracker should be connected to iCloud again. However, some books or changes may be missing (those not uploaded to iCloud before the issue).

To recover them:

1. On the same device where you created the manual backup at the beginning, open Settings > Backup & Restore.
2. Select the backup you created before.
3. Restore it.

Now your complete library will be back on the main device, and iCloud will sync it across all your devices.

Extra tips

• Keep Book Tracker in the foreground and connected to Wi-Fi until syncing finishes.
• Disable Low Power Mode on iPhone/iPad to prevent interruptions.
• Large libraries may take several minutes to re-upload.

👉 Apple’s guide: If iCloud isn’t working.