head to head · open source
calibre-web vs PyMuPDF
calibre-web has 18,216 GitHub stars, 1,863 forks, 409 open issues and last shipped yesterday. PyMuPDF has 10,744 stars, 800 forks, 58 open issues and last shipped 3 days ago. calibre-web leads on adoption by 70% (18,216 vs 10,744 stars). calibre-web is written in Fluent under GPL-3.0; PyMuPDF is written in Python under AGPL-3.0. calibre-web has attracted 10% as many forks as stars, PyMuPDF 7%. calibre-web was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (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.
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Side by side
| calibre-web | PyMuPDF | |
|---|---|---|
| GitHub stars | ★ 18K | ★ 11K |
| License | GPL-3.0 | AGPL-3.0 |
| Written in | Fluent | Python |
| Last push | 2026-09-19 | 2026-09-17 |
| Forks | ⑂ 1.9K | ⑂ 800 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick calibre-web if
- You weight community size — 18K stars and counting
- You want the GPL-3.0 license terms
- Your stack matches Fluent
- You value the larger contributor base for long-term maintenance
pick PyMuPDF if
- You want the PyMuPDF feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches Python
- You evaluated both and PyMuPDF fits your workflow better
About calibre-web
Calibre Web is a web application that provides a clean and intuitive interface for browsing, reading, and downloading eBooks from a valid Calibre database. It is a fork of the library project (calibreserver) and is licensed under the GPL v3. The project lives in the Calibre ecosystem, and it is distributed through PyPI as the calibreweb package as well as through Docker images. It has been developed for over eleven years and carries roughly 18,183 stars and 1,856 forks on GitHub.
read the full calibre-web overview →
About PyMuPDF
PyMuPDF is a high performance Python library, built on the MuPDF C engine, for extracting, analysing, converting, rendering and manipulating PDF and other documents, aimed at Python developers building data extraction, document processing and AI retrieval pipelines.
read the full PyMuPDF overview →
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Frequently asked questions
Is calibre-web or PyMuPDF more popular?
calibre-web has 18,216 GitHub stars and PyMuPDF has 10,744. calibre-web has the larger community by that measure.
Are calibre-web and PyMuPDF free?
Both are open source. calibre-web is licensed under GPL-3.0 and PyMuPDF under AGPL-3.0. Neither carries a licence fee.
What is the difference between calibre-web and PyMuPDF?
calibre-web is written in Fluent and PyMuPDF in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, calibre-web or PyMuPDF?
Choose calibre-web if you want the larger community (18,216 stars) or its GPL-3.0 licence terms. Choose PyMuPDF if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.