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

  • Edit book: Add a tool to make books accessible and checks for accessibility problems
  • Tools->Accessibility in the editor allows setting the languages of the book and its HTML files, editing the alternative text of every image (including inline SVG images) in one place and editing the EPUB Accessibility metadata. Check book now reports images without alternative text, HTML files without a language, headings that skip levels, elements with an epub:type but no matching ARIA role and missing accessibility metadata, many of which can be fixed automatically.
  • Edit book: Show a preview of colors as an underline and allow Ctrl clicking on colors to change them using a color wheel
  • Content server: Act as a progress sync server for KOReader
  • In KOReader, set the custom sync server to http://server:port/kosync and log in with the username and password of a Content server user. Reading positions are shared across different copies and formats of the same book.
  • Content server: Serve OPDS 2.0 feeds, with support for streaming CBZ comics, honoring the manga reading direction and searching book contents using the full text index
  • calibredb: Add commands to manage notes, annotations, data files, Virtual libraries, the trash bin and to rename and remove items such as tags and series
  • Content server: Many accessibility improvements for keyboard and screen reader users
  • E-book viewer: Allow searching only the current chapter
  • Content server viewer: Offer to rate the book and remove it from downloaded books when reaching the end
  • Searching: Add lastmonth, thisyear, lastyear, monthsago and yearsago for dates
  • EPUB Output: Set the language of HTML files and use the book title and language in generated cover pages
  • Get books: Add the Standard Ebooks, DOAB and DOAJ stores
  • calibre-debug: Allow verifying exported calibre data without restoring it
  • Read aloud: Resume interrupted voice downloads and time out stalled ones

Bug fixes

  • PDF Input: Improve page number detection and handling of large images. Closes tickets: 2172155
  • PDF Output: Fail with an error instead of hanging forever if the render process crashes or stops responding. Closes tickets: 2172711
  • TXT Output: Fix block elements nested after inline text not starting on a new line. Closes tickets: 2172704
  • RTF Output: Various minor bug fixes and hardening when generating RTF headers
  • RTF Input: Handle non-BMP Unicode characters correctly
  • TXT Input: Use UTF-8 instead of ASCII when the detected encoding is ASCII
  • EPUB Input: Prefer EPUB 3 landmarks over the legacy guide
  • KF8 Input: Fix invalid CSS when rewriting internal links
  • DOCX Input: Fix index sub-entries being merged under the wrong entry and keep multiple references to the same index entry on one line
  • Fix errors when reading some damaged EPUB files
  • Fix a crash when converting very small PDF files
  • Fix date searches using dots, spaces or month names comparing only the year
  • Fix searching for a number without a field matching truncated values in ratings and integer columns
  • Fix an error on every search after the Quickview panel has been closed. Closes tickets: 2172163
  • Saved searches: Do not allow invalid characters in the name. Closes tickets: 2172160
  • Trash bin: Mark removed formats of deleted books as not restorable
  • Fix sorting of merged highlights by position in the book
  • Windows: Fix an error opening EPUB files for the first time when antivirus software locks files. Closes tickets: 2172181
  • Windows: Prevent camoufox from creating a private browsing shortcut in the start menu on every launch
  • Create your own Adventure: Fix world generation failing with Gemini. Closes tickets: 2172371
  • Content server: Enforce per library restrictions in more places, including notes
  • Content server: Fix repeated highlight note editing, bookmark renames not syncing and data file deletion status
  • Notes: Fix importing some base64 encoded images
  • Fix a startup error when two store plugins have the same name
  • Fix a rare error during shutdown because of the thumbnail cache
  • calibredb restore_database: Exit with non-zero status on failure

Improved news sources

  • The Times and Sunday Times
  • Financial Times
  • The Boston Globe
  • Hacker News