Calibre is a free, open-source e-book library manager for organizing, searching, converting and transferring digital books. It catalogs multiple formats under one title, sorts books by metadata, and supports tags, comments and advanced searches. It can retrieve metadata and covers online, convert between common e-book formats, and send books to supported e-readers, converting files when needed.
| Author: | Kovid Goyal |
| License: | Open Source |
| Price: | FREE |
| Released: | May 28, 2026 |
| File size: | 212.00 MB |
| Downloads: | 3328 |
| Keywords: | read, transfer books to ereader, manage digital books, Open-source software, E-book Reader, E-book Synchronizer, Digital library, e-book, education, Calibre software, ebook reader software, ebook library manager, download rss news ebook, Kovid Goyal, manager, Portable, Windows 10 compatible, ebook format converter, library, E-book Management, Ebook management |
| Author URL: | https://kovidgoyal.net/ |
Calibre is a free, open-source e-book library manager for readers who want to organize, search, convert and transfer digital books from one desktop application. It treats each title as a single logical book, even when several file formats are stored for it, and lets users maintain a searchable catalogue rather than managing files one by one. Its library tools suit both casual readers and people with large collections who need consistent metadata and a flexible filing system.
Books can be sorted by details such as title, author, publication date, date added, size, rating and series. Tags provide custom categories, while comments can hold descriptions, notes or reviews. Search covers the library’s available fields, with advanced queries for more targeted results. Calibre can also retrieve metadata and cover images online using a book’s title, author or ISBN, helping fill in missing catalogue details. Selected books can be exported to disk in a folder structure configured by the user.
The built-in conversion tools transform e-books between many common formats. During conversion, Calibre can adjust font sizes, detect or create chapter structure and a table of contents, and add book metadata in a jacket at the beginning of an output file. This is useful when a book needs a different format or layout for a particular reading device. When transferring a title, Calibre selects an available format suitable for the connected device and can convert the book if no suitable format is already in the library.
Device synchronization can update book metadata and create device collections from library tags. Support is handled through a modular driver system for a wide range of e-readers. Calibre can also fetch articles from websites or RSS feeds, assemble full news stories into an e-book, and send the result to a connected reader. These features make it useful for keeping a portable reading collection current, preparing books for different devices, and collecting web publications alongside standard e-books.
Calibre is open-source software available for Windows, including Windows 10 and Windows 11. Its library, conversion and transfer functions are designed to work together: users catalogue titles, select books for a task, then export or send them without having to manage each format separately. The application is also known for including an e-book viewer for reading supported files on a computer. Device compatibility and available conversion options depend on the connected hardware and file formats involved.