JWJW Sync

Fixing a corrupted JW Library backup with Library Doctor

JW Library refuses to restore your .jwlibrary file? Library Doctor scans the backup in your browser, repairs common problems, and produces a clean copy that restores.

Sometimes JW Library refuses a backup file — the restore fails, errors out, or the file won't open. Common causes: an interrupted download, a cloud drive that mangled the file, an extension changed in transit, or internal inconsistencies that accumulated over years of use.

JW Sync includes Library Doctor, a checker that scans a .jwlibrary file and repairs the common problems — entirely in your browser, without the file ever leaving your device.

Step by step

  1. Open JW Sync and load the problem file

    Go to jwsync.org and load the .jwlibrary file that won't restore. (If the file arrived renamed to .zip, rename it back to .jwlibrary first — that alone fixes many cases.)

  2. Run the Library Doctor scan

    The Doctor examines the backup's internal structure and lists what it finds — from harmless quirks to real damage — in plain language.

  3. Apply the fixes

    One tap repairs what's repairable. The Doctor never edits your original file; it produces a cleaned copy, so the original stays untouched as a fallback.

  4. Download and restore the repaired file

    Restore the cleaned .jwlibrary via Backup and Restore → Restore in JW Library.

Do it now — free, in your browserJW Sync merges, edits and analyses .jwlibrary backups entirely on your device. No account, no uploads, nothing installed.Open JW Sync →

The Doctor also runs during every merge

The same checks run automatically inside the merge engine, so a merged backup is always delivered clean — even when one of the input files had problems you never knew about.

When a file is beyond repair

If the file was truncated badly enough that the data simply isn't in it, no tool can invent it back. The Doctor will say so honestly rather than produce a doubtful file — and that's the cue to hunt for an earlier copy in email, Drive or iCloud, which is also why keeping older backups is worth it.

Frequently asked questions

Is my data uploaded for the scan?
No. The scan, the fixes and the export all run locally in the browser.
Can it recover notes deleted inside JW Library?
No — it repairs file structure. Notes deleted in the app before the backup was made aren't in the file to recover.

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