head to head · open source
calibre vs epub-press-clients
calibre has 25,927 GitHub stars, 2,693 forks, 6 open issues and last shipped today. epub-press-clients has 618 stars, 87 forks, 96 open issues and last shipped 3 months ago. calibre leads on adoption by 4,095% (25,927 vs 618 stars). calibre is written in Python under GPL-3.0; epub-press-clients is written in JavaScript under GPL-3.0. calibre has attracted 10% as many forks as stars, epub-press-clients 14%. 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, epub, kindle), 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 8884 open source comparisons
Side by side
| calibre | epub-press-clients | |
|---|---|---|
| GitHub stars | ★ 26K | ★ 618 |
| License | GPL-3.0 | GPL-3.0 |
| Written in | Python | JavaScript |
| Last push | 2026-09-18 | 2026-06-25 |
| Forks | ⑂ 2.7K | ⑂ 87 |
| 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 epub-press-clients if
- You want the epub-press-clients feature set and don't need the biggest community
- You prefer the GPL-3.0 license terms
- Your stack matches JavaScript
- You evaluated both and epub-press-clients fits your workflow better
About calibre
calibre is the official source code repository for the calibre e book manager, an open source application written in Python and released under GPL 3.0. It lives in the content and publishing ecosystem as a desktop tool for books, and it is cross platform, running on Linux, Windows and macOS. The project has been hosted on GitHub for roughly thirteen years, carries about 25,900 stars and 2,683 forks, and its home on the web is calibre ebook.com, where an About page and a screenshots page document it further.
read the full calibre overview →
About epub-press-clients
epub press clients Easy to use clients for building ebooks with EpubPress. Backend code can be found in haroldtreen/epub press. Follow us on Twitter. Overview EpubPress is a service for stitching articles/blogs/webpages into a customized ebook. 🌟 Benefits 🌟 EpubPress makes reading the web more enjoyable! Downloads your articles for offline reading. Books are compatible with all your iPhone, Android, Kindle, Nook, etc. Removes website boilerplate and ads. Just. Clean. Content. Lets you group information together (eg. "News from this week", "Top 10 travel articles"). Easy to sharing with friends. Packages 📦 epub…
read the full epub-press-clients 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 epub-press-clients more popular?
calibre has 25,927 GitHub stars and epub-press-clients has 618. calibre has the larger community by that measure.
Are calibre and epub-press-clients free?
Both are open source. calibre is licensed under GPL-3.0 and epub-press-clients under GPL-3.0. Neither carries a licence fee.
What is the difference between calibre and epub-press-clients?
calibre is written in Python and epub-press-clients in JavaScript. 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 epub-press-clients?
Choose calibre if you want the larger community (25,927 stars) or its GPL-3.0 licence terms. Choose epub-press-clients if its feature set, stack or GPL-3.0 licence fits better. Both are self-hostable.