What it does
calibre is a free open-source ebook manager with conversion, metadata editing, reading, and device-transfer tools. Conversion can adjust style, navigation, punctuation, and margins.
Keep a book in the managed library while converting a copy for a reader. Edit title/author metadata and use manual settings to rebuild contents, adjust styles or margins, and change punctuation. Check the result in calibre’s viewer or on the target device, particularly for complex layouts. Device-aware delivery can choose a suitable format automatically. The Content server is a separate sharing route that exposes the library for remote reading.
Strengths
- Connects conversion with metadata, preview, and reader-device delivery.
Best for
- Managing ebooks that need several device-compatible formats
Sources
- calibre - About (Oct 26, 2026)