Which Ebook Reader Books Apps Sync Highlights Automatically?

I like a cleaner, quieter setup and what works for me is thinking in two layers: the app that creates highlights, and the service that aggregates them. On the app side, Kindle, Google Play Books, Apple Books, and Kobo all handle automatic sync pretty reliably — Kindle through Whispersync, Google Play through your Google account, Apple through iCloud, and Kobo with its Kobo cloud. They’ll carry notes and highlights to other devices as long as you’re logged in and sync is turned on.

On the aggregator side, Readwise has been a game-changer because it pulls in highlights from all of those apps plus Pocket and Instapaper, which are great if you highlight web articles. For Android fans who prefer native apps like Moon+ Reader, enabling cloud sync via Dropbox or Google Drive makes your local annotations behave like cloud-synced ones. One caveat: DRM'd library books can be finicky, and some library apps only sync reading position and bookmarks, not full highlight exports. I make it a habit to check the app’s sync settings and occasionally export or back up my highlights so I don’t lose the notes that matter.

If I had to give a quick list from my own use: Kindle, Google Play Books, Apple Books, Kobo, Pocket, Instapaper, and Moon+ Reader (with cloud enabled) all offer automatic highlight syncing in one form or another, and Readwise pulls many of these streams into a single, searchable collection. The main things to watch are account consistency (use the same login everywhere), app settings for sync or backup, and DRM restrictions — some publisher-protected files won’t let third-party tools read highlights. For PDFs I use apps that support cloud backups like Xodo or GoodReader so annotations don’t get stranded. If you want a single place to hang quotes, try connecting Readwise and a cloud drive; otherwise stick with the native ecosystem for the smoothest, nearly invisible syncing.

Honestly, I've bounced between a bunch of reading apps and the ones that consistently sync highlights automatically for me are the big-name ecosystems: Kindle, Google Play Books, Apple Books, and Kobo. Kindle syncs highlights and notes to Amazon's cloud as long as you have Whispersync enabled, and you can even see them on the 'Your Highlights' page in your Amazon account or pull them into other tools. Google Play Books keeps highlights tied to your Google account and syncs across Android, iOS, and the web. Apple Books uses iCloud so if you have multiple Apple devices, your highlights and bookmarks appear everywhere. Kobo also keeps reading position and annotations in sync via your Kobo account and their cloud.

If you want everything funneled into one place, add Readwise to the mix — it pulls highlights from Kindle, Apple Books, Google Play Books, Kobo, Pocket, Instapaper, and even PDFs or web highlights if you connect browser extensions. For Android readers who prefer local apps, Moon+ Reader can sync highlights via Dropbox or Google Drive if you turn on cloud sync, which is great when you want offline control but still want backups. Library apps like Libby/OverDrive usually sync reading position and bookmarks to your account; highlights can vary by format and publisher.

A couple of practical tips from my own messy library: always use the same account on all devices, check app settings for sync/backup, and be aware of DRM — some publisher-locked EPUBs/PDFs won’t let third-party services extract highlights. If you like collecting lines, Readwise or exporting a highlights file regularly saved to Dropbox/Drive will save you future headaches.