Less than a month after its previous 8.5 update, Calibre, the beloved open-source e-book management software, has rolled out version 8.6—a release that fine-tunes everything from database recovery to Kindle output formats.
First up, the Content Server now allows administrators to restrict users from changing their own passwords via the web interface. Additionally, the new build accelerates the database-restore routine by roughly an order of magnitude, trimming multi-minute waits down to mere seconds for large collections.
For those who rely heavily on series sorting, there’s a new tweak in “Preferences” > “Tweaks” to display series sort values directly in the Tag Browser. And speaking of defaults, the Welcome Wizard now sets AZW3 as the default output format for Kindle, replacing the outdated MOBI.
Searching and filtering just got a bit smarter, too, with new “not in” buttons in Manage Authors and Manage Items, making it easier to exclude specific entries from searches.

Regarding bug fixes, Calibre 8.6 tackles several. Windows users will no longer see mysterious terminal windows flashing when adding or converting PDFs—a regression from the previous release.
The background image fade effect, which was broken in version 8.4, has been restored. Meanwhile, non-English language books now correctly support series-based searches by first letter in the Tag Browser.
Metadata editors will appreciate that the “Next/Previous” buttons in “Edit Metadata” Individually now work reliably, even if the book list gets reordered. And for those plagued by permission errors when generating catalogs on Windows, Calibre now includes a workaround for systems where overzealous antivirus software locks files unnecessarily.
Lastly, Calibre 8.6 welcomes La Presse by quatorze as a new news source, while several existing ones—including The Economist, Financial Times, PC World, and The Times of India—have received updates for better reliability and formatting.
Check out the changelog for more details and the complete list of novelties in the Calibre 8.6 open-source e-book management tool. The update is already live for Windows, macOS, and Linux.