How to merge JW Library backups from two devices
Combine the notes, highlights, bookmarks and tags from two or more JW Library backups into one .jwlibrary file — free, private, in your browser.
If you study on more than one device — a phone at the hall, a tablet at home — each device ends up with its own notes and highlights. JW Library's built-in Backup and Restore can't combine them: restoring one backup replaces everything on the device, wiping out the other device's work.
JW Sync solves this. It reads two (or more) .jwlibrary backup files and merges the notes, highlights, bookmarks and tags from all of them into one new backup file. The merge runs entirely in your browser — your files are never uploaded to any server, so your personal study notes stay private.
Step by step
Create a backup on each device
In JW Library, open Personal Study, tap the three-dot menu, choose Backup and Restore, then Create a backup. Do this on every device. Each one produces a .jwlibrary file.
Open JW Sync
Go to jwsync.org in any browser — on your phone, tablet or computer. Nothing to install.
Load both backup files
Drop in (or pick) the .jwlibrary files. JW Sync reads them locally on your device.
Review the pre-merge preview
Before anything is written, a preview shows exactly what will be combined. If the same note was edited differently on each device, the Conflict Reviewer shows both versions side by side with a word-level diff so you choose which to keep — or let “Suggest best” pick for you.
Download the merged file and restore it
Download the merged .jwlibrary file, then restore it on each device via Backup and Restore → Restore. Both devices now carry the complete, combined library.
What gets merged?
Notes, highlights, bookmarks, tags and their connections. Duplicates are detected automatically, so restoring the merged file never doubles anything up. Backups from Android, iPhone, iPad and the Windows app all use the same format and merge together freely.
Is it safe?
The merge never modifies your original files — it produces a brand-new backup, so your originals remain untouched as a fallback. And because everything runs client-side in the browser, no data leaves your device.
Frequently asked questions
- Can I merge more than two backups?
- Yes — load as many .jwlibrary files as you have devices. They are all combined into a single merged backup.
- Will merging create duplicate notes?
- No. Identical notes, highlights and bookmarks are detected and kept once. Genuinely different versions of the same note are surfaced in the Conflict Reviewer for you to decide.
- Does it work between Android and iPhone?
- Yes. The .jwlibrary format is identical across Android, iOS, iPadOS and Windows, so backups from different platforms merge without any conversion.