Calibre 9.9 has been released as the latest update to the popular open-source e-book manager, with the Content Server introducing a modern interface with a sidebar to improve navigation when browsing libraries in a browser.
PWA support has also been added. When accessed over HTTPS, the Content Server can now be installed as a Progressive Web App, allowing easier access from desktop or mobile launchers while still running in the browser.
Moreover, the book editor now supports keyword-based filtering for saved searches, making it easier to locate stored searches. The image compression tool also adds an option to convert PNG images to JPEG or WEBP, which can help reduce file sizes.
Calibre 9.10 now also supports CSS Level 4 selectors in its CSS parser, increasing compatibility with modern stylesheet rules in e-book editing and conversion workflows.
The cover grid now scales images larger than the viewport to fit appropriately. Plus, the annotations browser also allows filtering by custom annotation styles, giving users greater control over annotation management.
On the bug-fix side, the e-book viewer resolves an issue on Windows in which IME input did not function correctly when typing notes for highlights. Conversion heuristics have been optimized for certain cases, and SNB input management has been improved for specific files.
Windows users receive a fix for a rare crash caused by excessive notifications. Additionally, duplicating books now correctly preserves values from enumerated columns with defined default values.
Calibre 9.10 also restores visibility for errors reported by AI plugin providers, addressing a regression from version 9.8 where these errors were not displayed to users. Other fixes include a valid CSV export for the comments field and a security update that disallows the use of Python templates when reading book metadata.
Finally, the built-in news sources for The Week, Economist Espresso, and Horizons have also been improved.
For additional details, see the announcement. Calibre 9.10 is available for Windows, macOS, and Linux.
