Calibre is a one-stop manager for e-books that helps you organise a growing library, convert books between formats and send them to a reader. It also includes a built-in viewer and tools for editing book details, so your collection stays tidy and easy to search. Readers who collect books from different sources will find it especially handy.
Related tools: Zotero, Logseq, and more in Research & More.
Label: Open-source
Platform: Windows, macOS and Linux
Best for: Organising, converting and reading e-books
Replaces: Paid e-book managers and reader apps
Verified: 31 October 2026