head to head · open source
calibre vs PolyglotPDF
calibre has 26,327 GitHub stars, 2,743 forks, 6 open issues and last shipped yesterday. PolyglotPDF has 1,324 stars, 198 forks, 14 open issues and last shipped 1.1 years ago. calibre leads on adoption by 1,888% (26,327 vs 1,324 stars). calibre is written in Python under GPL-3.0; PolyglotPDF is written in Python under GPL-3.0. calibre has attracted 10% as many forks as stars, PolyglotPDF 15%. calibre was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (ebook), 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 | PolyglotPDF | |
|---|---|---|
| GitHub stars | ★ 26K | ★ 1.3K |
| License | GPL-3.0 | GPL-3.0 |
| Written in | Python | Python |
| Last push | 2026-11-02 | 2025-09-28 |
| Forks | ⑂ 2.7K | ⑂ 198 |
| 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 PolyglotPDF if
- You want the PolyglotPDF feature set and don't need the biggest community
- You prefer the GPL-3.0 license terms
- Your stack matches Python
- You evaluated both and PolyglotPDF 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…
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About PolyglotPDF
python包在2.2版本之前预计不会更新，2.2版本预估采取解析最底层span获取更信息的布局逻辑解决，预估解决：行内公式错误判断为公式块，错误将粗体文本进行分段bug,以及insert html方法重复嵌入字体文件导致处理页数较大pdf时浪费计算资源极其卡顿。 目前效果，对于基于文本的pdf,polyglotpdf的解析方式依旧是最优解。 ocr和布局分析并不总是完美。（考虑处理文本上下标问题，大部分pdf文件中上标下标文本通过指定坐标和字体大小实现伪上下标，考虑替换为真正的上下标文字对应的Unicode编码，但并不完美），对于报告型表格文档，polyglotpdf效果相当完美，当然表格中的复杂矢量数学公式依旧无法正确处理）。 寻求意见的改进方法，对于复杂的颜色布局文本或者粗体参杂常规字体文本，提出以下方法，对于流内容我们可以解析为html格式如下： ABSTRACT: The swine industry annually suffers significant economic losses caused by porcine reproductive and respiratory syndrome virus (PRRSV). Because the available commercial vaccines have limited protective efficacy against epidemic…
read the full PolyglotPDF overview →
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Frequently asked questions
Is calibre or PolyglotPDF more popular?
calibre has 26,327 GitHub stars and PolyglotPDF has 1,324. calibre has the larger community by that measure.
Are calibre and PolyglotPDF free?
Both are open source. calibre is licensed under GPL-3.0 and PolyglotPDF under GPL-3.0. Neither carries a licence fee.
What is the difference between calibre and PolyglotPDF?
calibre is written in Python and PolyglotPDF 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 or PolyglotPDF?
Choose calibre if you want the larger community (26,327 stars) or its GPL-3.0 licence terms. Choose PolyglotPDF if its feature set, stack or GPL-3.0 licence fits better. Both are self-hostable.