Inksky
You finish a chapter on your Kindle, pick up the Kindle app on your phone, and… you’re three chapters behind. Or your Kobo’s sync button spins for two minutes before giving up with no error message. Sync failures are the most frustrating kind of e-reader problem because they’re invisible — you don’t know something’s broken until you’ve already lost progress. Here’s how to fix the most common ones.
Kindle: Whispersync position drift
Whispersync is supposed to keep your reading position synchronized across every device and app linked to your Amazon account. When it drifts, the mismatch is almost always caused by one of two things:
The book was sideloaded, not purchased from Amazon. Whispersync only works for books in your Kindle library that Amazon recognizes — purchased books, Kindle Unlimited borrows, and books sent through Send to Kindle. Books transferred via USB do not sync. This trips up people coming from Calibre who copy books directly to the device. The fix: use Send to Kindle (the web uploader or the Send to Kindle app) instead of USB. The book becomes part of your Amazon cloud library and Whispersync kicks in.
You opened the book on multiple devices simultaneously. If your Kindle and phone app both have the same book open, and the Kindle hasn’t synced before you put it to sleep, the phone app may “win” because it syncs more aggressively. Force-sync on the Kindle before switching devices: tap the top of the screen to open the menu, then tap the sync icon. A checkmark confirms it went through. Do this whenever you’re about to switch from Kindle to phone and you’ll never lose your place.
Kobo: the spinning sync button
Kobo’s sync button (the circular arrows icon on the home screen) is notoriously temperamental. If it spins indefinitely:
- Turn Wi-Fi off and on. Seriously — this fixes it about half the time.
- If that doesn’t work, restart the Kobo (hold the power button, select Restart).
- Still spinning? Go to Settings → Accounts → Kobo and sign out, then sign back in. This does not erase your sideloaded books — those live on the device storage and survive a sign-out. You will lose reading stats that haven’t synced to Kobo’s servers, so let the sync complete (or fail definitively) before signing out.
The underlying cause is usually a stale authentication token. Kobo’s token refresh mechanism is less robust than Amazon’s, and after a firmware update it occasionally breaks. Signing out forces a fresh token.
Highlights that don’t sync
On Kindle, highlights sync through Whispersync and appear at kindle.amazon.com/your_highlights. If they’re on your device but not online: make sure the book is in your Amazon cloud library (not USB-sideloaded), force-sync while connected to Wi-Fi, and give it a few minutes. Highlights don’t sync in real time — there’s always a delay, and it’s longer for heavily highlighted books.
On Kobo, highlights only sync for books purchased from the Kobo Store. Sideloaded books — even those loaded through Adobe Digital Editions — store highlights locally only. There’s no cloud backup for sideloaded highlights on Kobo. This is one of the strongest arguments for buying from Kobo directly if you annotate heavily. To back up highlights from sideloaded books, connect your Kobo to a computer and copy the KoboReader.sqlite file from the .kobo directory. The annotations table inside it contains everything.
”Book purchased but not appearing”
On Kindle: go to Settings → Device Options → Advanced Options → Whispersync for Books and confirm it’s enabled. Then go to your library, pull down to refresh, and check that your filters aren’t hiding it — “All” instead of “Downloaded.”
On Kobo: the sync only fetches the last 3-4 purchases by default. Older purchases may not appear. Search for the title on your Kobo. If it still doesn’t show, go to the Kobo website on a computer, open My Books, and confirm the purchase is associated with the same account. Kobo’s storefront and reading app sometimes use separate account systems in certain regions.
Account region mismatches
Kindle: Amazon accounts are region-specific. A book purchased on Amazon.com (US) may not sync to a Kindle registered to Amazon.co.uk (UK). If you’ve recently moved countries or switched storefronts, check that all your devices are registered to the same regional account. You can change your Kindle’s region under Settings → Your Account → Country/Region Settings, but be aware that this may affect your Kindle Unlimited and Prime Reading access.
Kobo: Kobo enforces region restrictions based on the billing address on your payment method. A book available on Kobo US may not appear for a Kobo Canada account. There’s no supported way to switch between regional stores — you’d need a separate Kobo account for each region, which defeats the purpose of syncing.
The nuclear option: deregister and re-register
On both Kindle and Kobo, deregistering the device erases all account associations and local data, then re-registering pulls everything fresh from the cloud. What you lose: downloaded books (they re-download), device-specific settings (you’ll redo them), and on Kobo, sideloaded content (it stays on storage but won’t be re-indexed automatically). What you gain: a clean authentication state, fresh sync tokens, and in most cases, working sync again.
For Kindle: Settings → Your Account → Deregister Device. For Kobo: Settings → Device Information → Factory Reset, then set up fresh. Do this only after trying everything else — it’s a hassle — but it fixes sync problems that nothing else touches. I’ve done it twice in 8 years of e-reader ownership. Both times it solved the problem immediately.
If the nuclear option doesn’t fix it, the problem is server-side and you should contact Amazon or Kobo support.