[Update] 2026-07-27 - Library performance, storage templates

[Erlend]

This update brings huge performance improvements to everything related to handling your library, including file operations, downloads, synchronization, and browsing. It also adds a new storage template system, which lets you decide how your books are stored, and some smaller usability improvements.

• Implemented storage templates, which lets you decide how your files are stored (for example in a folder per author, or a folder per series).
• Improved customization of which info to show on books in the library, using the same template system as the storage templates.
• Greatly improved performance when loading huge libraries from Calibre content servers, cloud providers, the local library, and external folders.
• Added a 'Part of series' filter to the library filter system.
• Added custom sorts, which can be created by combining multiple of the base sorts.
• Improved performance and feedback when running a book source synchronization.
• Book source synchronization can now be minimized and continue working in the background.
• Now stores passwords and tokens for book source and data synchronization connections securely.
• Fixed parsing of MOBI files without internal compression.
• Fixed 'Open in' action not working correctly when books were stored on external storage.
• Fixed some controls (most notably the selected radio button in a list) being invisible due to wrong theme colors being set in native Android.
• Merged the dictionary/AI lookup into the text selection popup to make it easier to use.
• If a selected word has a stored dictionary/AI lookup, it will now be shown immediately in the text selection popup.
• When adding new Calibre book sources, you can now choose to copy the username and password from an existing connection instead of having to enter it again.