Multiple backups. Merged. Without losing anything.
JW Merge brings together highlights, notes and bookmarks from all your devices into a single backup. Everything happens in your browser: nothing is uploaded, your original files stay untouched.
Add
Drop your .jwlibrary files. They never leave your device.
Merge
Everything is faithfully merged, and we show you the rare choices to make yourself.
Download
Get a single backup, ready to reimport into JW Library.
How it works, in detail.
The principle is simple: everything is kept. Here is exactly how each case is handled, including the rare moments where it's up to you to choose.
How do I create a backup in JW Library?
In JW Library, open the Personal Study tab, tap the cloud icon at the top, then Create a backup. Do this on each device: you get one .jwlibrary file per device, and those are the files you drop here.
Are my original files modified?
No, never. Everything happens in your browser: your .jwlibrary files are never sent, modified or deleted. You get a brand-new backup, and your originals stay intact as a safety net.
How are highlights brought together?
Every highlight from every device is kept. When two devices highlight different passages, they simply add up. A “conflict” only appears when the same passage is highlighted in two different colors depending on the device.
What happens when highlights overlap?
JW Library shows only one color per word: two colors can't sit on the same words. When one highlight fully covers another, we keep the more complete one by default (the other would be invisible anyway). When they only partly overlap, we keep both: each device's own portion stays visible, and the shared portion takes a single color. You can always choose, passage by passage, which version to keep.
When can there be a loss, and what is kept?
No visible highlight is lost automatically. When one highlight fully covers another, keeping “both” would show nothing more (only one displays), so we keep the more complete one by default. When the overlap is only partial, we keep everything. There is a real loss only if you deliberately choose to keep a single version of a passage: in that case only the overlapping highlight is removed, never the other highlights of the device. For the Bible and heavily annotated documents, each conflicting passage is shown to you so you can review and adjust.
What about my notes?
Each note is tracked individually. If the same note was edited differently on two devices, we keep the most recent version by default and show you both, so you can compare, choose, or combine both versions into a single note. Nothing is lost without your say-so.
How do bookmarks work?
All your bookmarks are carried over. JW Library limits each publication to 10 bookmarks. If merging your devices pushes a publication past that limit, the extra bookmarks are first moved to a free slot when possible. Beyond 10, those that don't fit can't be kept, so we list them by name so you know exactly which ones.
What about my study answers?
They are all carried over. If the same question has a different answer depending on the device, we keep the longest answer by default (usually the most complete).
What if a backup comes from a newer version of JW Library?
JW Merge merges everything it recognizes. If a backup contains data from a version newer than what we can handle, that specific data is not merged to avoid corruption. It is clearly flagged in the result.
Is JW Merge free?
Yes, JW Merge is completely free. No account, no sign-up, no hidden fees. The tool runs entirely in your browser.
Is JW Merge safe to use?
Yes. Your .jwlibrary files never leave your device: everything is processed locally in your browser using WebAssembly. No data is uploaded to any server. Your original files are never modified or deleted.