Frequently asked questions
Everything about backing up and restoring your Kobo e-reader with KoBup.
Getting started
What is KoBup?
KoBup is a free, open-source web tool that backs up and restores Kobo e-readers directly in your browser. It reads your books, highlights and reading progress locally and saves them into a ZIP file on your computer.
Which browsers are supported?
Backups and the library work in all modern desktop browsers. Restoring needs the File System Access API to write to the Kobo, available in Chrome, Edge, Opera and Brave on a computer.
Do I need an account?
No. There is no registration and no login. KoBup has no server that could store your data.
Is it free?
Yes, completely. It is a personal open-source project under the MIT license.
Backup & restore
What does a backup contain?
The Kobo database (reading progress, highlights, notes, bookmarks, collections) and, optionally, your sideloaded book files, reading settings, custom fonts and sleep screens. Books bought from the Kobo store are not included: you can download them again from your account.
Can I move my library to a new Kobo?
Yes. Choose “Merge reading data” when restoring: progress, highlights and collections are added to the new Kobo while it keeps its own account and settings.
Will restoring delete my current books?
No, unless you explicitly choose to delete the existing book folders. Before changing the database, KoBup saves a copy of it on the Kobo so you can undo the restore.
How do I know a backup is good?
Right after writing, KoBup reads the archive back, checks every file is there and compares the database checksum. You can verify it again later from the History page.
How long does it take?
A database-only backup takes seconds. A full backup depends on your library size and USB speed: a few minutes for several gigabytes.
Privacy & security
Is my data sent to a server?
No. Everything runs in your browser with JavaScript and WebAssembly. The site’s Content Security Policy only allows connections to its own origin, so the page cannot upload your library.
Why would I encrypt a backup?
The Kobo database also stores your Kobo account sign-in tokens. If you keep backups in the cloud, a password (AES-256) makes sure nobody else can use them.
Does KoBup use analytics or cookies?
No cookies. The site uses cookieless Vercel Analytics to count anonymous page views; it never sees your library or backup files.
Is it affiliated with Rakuten Kobo?
No. KoBup is an independent community tool, not endorsed by Rakuten Kobo Inc.
Technical
Does it work offline?
Yes. After the first visit the app is cached and can be installed, so it keeps working without an internet connection.
Can I use it on a phone or tablet?
Not really: mobile browsers cannot access a USB-connected Kobo. Use a desktop or laptop computer.
Why are my book covers missing?
Covers come from the thumbnails your Kobo generated. Books you never opened in the library view may not have one yet; KoBup then draws a placeholder.
Still have questions?
Read the step-by-step guide or open an issue on GitHub.