Calibre (software)

Calibre
Original authorKovid Goyal
Initial release31 October 2006 (2006-10-31)
Stable release
9.5.0  / 13 March 2026
Written inPython, C++, C
Operating systemWindows, macOS, Linux
PlatformIA-32, x64
TypeE-book reader, word processor
LicenseGPL-3.0-only
Websitecalibre-ebook.com
Repository

Calibre (/ˈkælɪbər/ KAL-ih-bər) is a cross-platform free and open-source suite of e-book software. Calibre supports organizing 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. The editing of books is supported for EPUB and AZW3 formats. Books in other formats like MOBI must first be converted to those formats, if they are to be edited. Calibre also has a large collection of community contributed plugins.