head to head · open source
calibre vs kepubify
calibre has 26,327 GitHub stars, 2,743 forks, 6 open issues and last shipped yesterday. kepubify has 899 stars, 59 forks, 29 open issues and last shipped 11 months ago. calibre leads on adoption by 2,828% (26,327 vs 899 stars). calibre is written in Python under GPL-3.0; kepubify is written in Go under MIT. calibre has attracted 10% as many forks as stars, kepubify 7%. calibre was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (ebook, ebooks, epub), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
← all 20902 open source comparisons
Side by side
| calibre | kepubify | |
|---|---|---|
| GitHub stars | ★ 26K | ★ 899 |
| License | GPL-3.0 | MIT |
| Written in | Python | Go |
| Last push | 2026-11-02 | 2025-12-06 |
| Forks | ⑂ 2.7K | ⑂ 59 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick calibre if
- You weight community size — 26K stars and counting
- You want the GPL-3.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick kepubify if
- You want the kepubify feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Go
- You evaluated both and kepubify fits your workflow better
About calibre
calibre calibre is an e book manager. It can view, convert, edit and catalog e books in all of the major e book formats. It can also talk to e book reader devices. It can go out to the internet and fetch metadata for your books. It can download newspapers and convert them into e books for convenient reading. It is cross platform, running on Linux, Windows and macOS. For more information, see the calibre About page. Screenshots Screenshots page Usage See the User Manual. Development Setting up a development environment for calibre. A tarball of the source code for the current calibre release. Bugs Bug reports and…
read the full calibre overview →
About kepubify
kepubify Kepubify converts EPUBs to Kobo EPUBs. Website Download Documentation Web Version pkg.go.dev About Kepubify is standalone (it also works as a library or a webapp), converts most books in a fraction of a second (40 80x faster than Calibre), handles malformed HTML/XHTML without causing further issues, has multiple optional conversion options (punctuation smartening, custom CSS, text replacement, and more), has a full test suite, is interoperable with other applications, and is safe to use with untrusted books. Two additional standalone utilities are included with kepubify. covergen pre generates cover…
read the full kepubify overview →
More in Content & Publishing
Related comparisons
More Publishing projects
Compare either of these against the rest of the Publishing field.
Frequently asked questions
Is calibre or kepubify more popular?
calibre has 26,327 GitHub stars and kepubify has 899. calibre has the larger community by that measure.
Are calibre and kepubify free?
Both are open source. calibre is licensed under GPL-3.0 and kepubify under MIT. Neither carries a licence fee.
What is the difference between calibre and kepubify?
calibre is written in Python and kepubify in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, calibre or kepubify?
Choose calibre if you want the larger community (26,327 stars) or its GPL-3.0 licence terms. Choose kepubify if its feature set, stack or MIT licence fits better. Both are self-hostable.