Calibre is an e-book library manager. It can view, convert and catalog e-books in most of the major e-book formats. It can also talk to many e-book reader devices. It can go out to the Internet and fetch metadata for your books. It has a cornucopia of features divided into the following main categories:

  • Library Management
  • E-book conversion
  • Syncing to e-book reader devices
  • Downloading news from the web and converting it into e-book form
  • Comprehensive e-book viewer
  • Content server for online access to your book collection

Is Calibre an e-book reader?

No, Calibre is an e-book manager in which you can organize existing e-books into virtual libraries, displaying, editing, creating and converting e-books, as well as syncing e-books with a variety of e-readers.

Can I write an e-book with Calibre?

Yes. Calibre can turn your personal documents to e-books or create them from scratch. It has automatic style helpers and scripts generating the book's structure.

Which devices does Calibre support?

Calibre is compatible with almost any e-reader, phone or tablet, as well as Windows, Mac and Linux devices. You can transfer your e-books from one device to another in seconds. Calibre will send the best file format for your device, converting it if needed, automatically.

What formats does Calibre support conversion to/from?

Calibre supports the conversion of many input formats to many output formats such as:

  • Input Formats: AZW, AZW3, AZW4, CBZ, CBR, CB7, CBC, CHM, DJVU, DOCX, EPUB, FB2, FBZ, HTML, HTMLZ, LIT, LRF, MOBI, ODT, PDF, PRC, PDB, PML, RB, RTF, SNB, TCR, TXT, TXTZ
  • Output Formats: AZW3, EPUB, DOCX, FB2, HTMLZ, OEB, LIT, LRF, MOBI, PDB, PMLZ, RB, PDF, RTF, SNB, TCR, TXT, TXTZ, ZIP.

Can Calibre read RSS feeds?

Yes, Calibre can deliver news to your device from hundreds of news sources or any RSS feed.

Does Calibre offer cloud storage for my library?

Calibre doesn't offer cloud storage, but it does integrate with most major cloud providers, including Google Drive, Dropbox, and OneDrive. This way, you can set up your eBook library in the cloud and access the content from your phone or tablet.

What's New

New features

  • Content server: A new "modern" interface with a sidebar to ease navigation
  • Content server: When used with HTTPS allow installation as a PWA (Progressive Web App)
  • Edit book: Saved searches: When filtering the list of saved searches match by keywords. Closes tickets: 2156386
  • CSS parsing: Add support for CSS Level 4 selectors. Closes tickets: 2156213
  • Cover grid: When using an image larger than the viewport as a texture scale it to fit the viewport. Closes tickets: 2154669
  • Annotations browser: Allow restricting displayed annotations by custom annotation styles as well. Closes tickets: 2154593
  • Edit book: Compress images: Add option to convert PNG images to JPEG or WEBP

Bug fixes

  • E-book viewer: Fix IME on Windows not working when typing in notes for highlights. Closes tickets: 2049604
  • Conversion: Heuristics: Improve performance in some pathological cases
  • SNB Input: Fix error on some input files
  • Windows: fix rare crash when too many notifications are displayed at once
  • Fix duplicating of books not duplicating value from enumerated columns when the column has a default value defined. Closes tickets: 2103999
  • Fix a regression in 9.8 that caused errors from AI plugin providers to be silently swallowed and not displayed to user
  • Fix CSV export invalid when exporting comments field. Closes tickets: 2155175
  • Disallow Python templates when reading book metadata (CVE-2026-53511)

Improved news sources

  • The Week
  • Economist Espresso
  • Horizons