Calibre Download: Get the Official Free eBook Manager

The official download page is calibre-ebook.com/download. You choose Windows, macOS, Linux or Portable, and each page links the installer plus an alternate download location. The download page also publishes signatures for all installer files, so careful users can check that a file has not been altered.

Calibre is free. The site asks for voluntary donations to support development, but nothing is locked behind payment. A site that sells "calibre Pro" or a licence key is not the official project.

At the time of writing the current release is calibre 9.16.0. Requirements differ by system, and the official pages point older computers to the last version that works for them:

• Windows: the current 64-bit build runs on Windows 10 version 1809 and higher. For older Windows 10 builds the site points to calibre 7.26, for Windows 8 to calibre 5.44, and for Windows 7 or Vista to calibre 3.48, all from its own archive.
• macOS: the current build needs macOS 14.0 (Sonoma) or newer. Older Macs are directed to earlier versions, for example 7.26 for macOS versions before Sonoma.
• Linux: the project recommends its own binary installer over distribution packages, which it says are often outdated. The installer runs on 64-bit Intel or ARM machines and needs a reasonably recent system library (GLIBC 2.34 or higher).
• Portable: a self-contained Windows build for Windows 10 or later that keeps the program, libraries and settings together, for example on a USB drive.

The site notes that uninstalling a newer version and installing an older one does not affect your books or settings. Even so, back up your library folder before any change.

1. Open calibre-ebook.com/download and choose your operating system.
2. On Windows, click "Download calibre 64bit" and run the installer. On macOS, open the .dmg and drag calibre to Applications; the site notes that it cannot run from inside the .dmg.
3. On first launch, the Welcome wizard asks where to keep your library. Choose a folder with enough space that you back up regularly, such as a folder inside Documents.
4. Select your e-reader model if you have one, so calibre converts books to a format it can read.
5. Click Add books and choose your DRM-free EPUB, PDF or other files. Calibre copies them into its library and fetches covers and details if you ask it to.

Keep calibre's library folder separate from the folder you download books into. Calibre manages its own folder structure, and editing it by hand can confuse the library database.

Calibre's strength is handling many formats in one place:

• Convert books: select a title and click Convert books to turn an EPUB into AZW3 for a Kindle, or the other way round. Converting a complex PDF to EPUB often needs some tidying, because PDFs fix text to the page layout.
• Read on the computer: the built-in viewer opens most formats with adjustable fonts and themes. If you prefer a separate reading app, our eBook reader guide compares Thorium Reader, SumatraPDF and others.
• Send to a device: plug in your e-reader, phone or tablet with a USB cable and calibre shows it as a device, so you can copy books across.
• Edit metadata: fix titles, authors, series and covers so your library sorts correctly.

For plain PDF documents rather than books, a lighter app from our PDF reader guide is usually quicker to open.

Despite searches for "calibre download for Android" or "calibre for iPad", calibre itself does not run on phones or tablets. The official Android and iOS pages explain two ways to connect instead: plug the device into the computer running calibre with a USB cable, or use the calibre Content server to browse your library and read books in a phone's web browser over your home network. Apps in the stores that use the calibre name are made by other developers, so check who publishes them before installing.

Calibre works with DRM-free books. The official FAQ explains that most purchased EPUB books carry DRM, which prevents calibre from opening them, although calibre can still store them and transfer them to an authorised e-reader. Books bought in the Kindle store are best read in Amazon's own apps. Calibre does not include DRM removal, and you should avoid add-ons or sites that promise it; besides breaking store terms, they are a common source of malware.

As with any popular free program, fake copies circulate on download portals and in search ads. Download only from calibre-ebook.com, compare the file with the official signatures if you want extra assurance, and scan anything unexpected. Our guides on verifying downloaded files and open source vs freeware explain why that matters.