Merge JW Library backups privately in your browser
Merge, browse, and edit your JW Library notes, highlights, and bookmarks — entirely in your browser. Your files never leave your device.
Choose a tool
Everything you need to merge and manage your JW Library notes
Local-only processing
All merging happens in your browser via WebAssembly. No server. No uploads. Complete privacy.
Tags & highlights merged
Intelligently combine tags, highlights, bookmarks and margin notes across all your backups.
Date-specific extraction
Extract content from a specific backup date to restore exactly what you had at any point in time.
Browse & edit notes
Search your entire library, edit notes, manage tags, change highlight colours, then download the updated backup.
Review before you download
See exactly which notes were edited on more than one device and choose which version wins — full transparency, no black box.
How to merge your JW Library backups
- Export a backup. Create a backup in JW Library on each device (menu → Settings → Backup & Restore → Create Backup).
- Add your main backup. Open JW Sync and add the backup from your primary device as the first file.
- Add your other backups. Add the .jwlibrary files from your other devices as additional files.
- Review the merge. Check the impact summary and choose which version wins for any conflicting notes.
- Download and restore. Download the merged .jwlibrary file and restore it in JW Library on your devices.
Frequently asked questions
Do my files get uploaded anywhere?
No. JW Sync runs entirely in your web browser. Your .jwlibrary backup files are never uploaded to any server — every step of the merge happens on your own device, so your notes stay private.
How do I merge JW Library backups from two phones?
Export a backup from JW Library on each device, then open JW Sync, add the first backup as your main file and the others as additional files, and merge. Download the combined .jwlibrary file and restore it in JW Library.
What is a .jwlibrary file?
A .jwlibrary file is the backup that the JW Library app creates. It contains your notes, highlights, bookmarks and tags. JW Sync reads these files and combines them into one.
Does JW Sync work on iPhone and Android?
Yes. JW Sync works in any modern browser on iPhone, iPad, Android and desktop. You can also install it as an app and use it offline.
Will merging overwrite my notes?
No. JW Sync combines your backups, and when the same note was edited on two devices it shows you both versions so you can choose which one to keep before you download.
Is JW Sync free?
Yes. JW Sync is completely free and works without an account or sign-up.
Have a question or need help?
Whether you hit a snag, have feedback, or just want to say hello — reach out and we'll get back to you.
jwsyncsupport@gmail.com