Calibre, the free and open-source e-book management software, has released version 9.17 with support for reading JPEG XL images during e-book conversion. The conversion engine also now supports CSS Level 4 selectors, improving its ability to process more modern styling rules found in e-books.
Another notable improvement concerns conversion speed. Calibre 9.17 introduces faster compression for MOBI, AZW3, and PDB output formats, reducing the time needed to convert books into these formats.
Users managing large e-book collections should also see performance improvements. Adding books and starting Calibre is now faster when the Tag browser is hidden, helping reduce delays in libraries containing thousands of titles.
On the accessibility side, the content server and built-in e-book viewer now respect the operating system’s prefers-reduced-motion setting. Additionally, the book editor’s validation tool can detect dangling ARIA references and update them automatically when fixing invalid element IDs.
The release also addresses two conversion regressions introduced in Calibre 9.16. One caused certain PDF files to fail during conversion, while the other generated invalid navigation markup when converting to EPUB 3. Both issues have now been corrected.
PDF output receives another fix for unwanted blank pages appearing at the end of chapters in some multi-column layouts. Moreover, ODT imports now correctly preserve restarted list numbering.
Several improvements target metadata and library management. Amazon and Google Images metadata sources have been restored using Camoufox, while fixes address stale cached values in custom columns and searches, incorrect series handling, and problems when appending multiple values to custom columns.
The content server also receives attention, particularly when working with multiple libraries. Fixes prevent books from the wrong library being displayed after switching collections and ensure full-text search actions operate on the currently selected library rather than the default one.
Additional changes improve dark-mode readability, keyboard focus styling, Kobo and Tolino device compatibility, and various database operations involving book files, notes, and formats.
Finally, Calibre 9.17 updates its built-in news sources, including The Economist, Associated Press, The Washington Post, Scientific American, and several others.
For more information, see the release notes. Calibre 9.17 is available for Linux, Windows, and macOS from the project’s website.
