If you have a folder of EPUB and MOBI files from different sources and want them in one searchable library that also feeds your e-reader, calibre is built for that job. Kovid Goyal wrote it, and the Windows build is version 9.17.0, released October 23, 2026, at 229.1 MB. The installer comes straight from the developer's server, download.calibre-ebook.com, not from us.
First steps: build a library and fetch metadata
After installing, add your existing books so calibre can catalog them. It is an e-book manager that views, converts, edits and catalogs books in all of the major formats, so the library is the center of everything else.
Next, let it go online for metadata. The program can fetch book details from the internet, and this release makes the Amazon and Google Images metadata sources work again using camoufox. If you own a reader device, calibre can also talk to it.
Conversion, newspapers and the 9.17.0 changes
Conversion is the headline skill. This version adds support for reading JPEG XL images and CSS Level 4 selectors, and it speeds up compression for MOBI, AZW3 and PDB output. The edit-book checker now flags dangling ARIA references.
Calibre can also download newspapers and turn them into e-books for later reading. Large libraries get a boost too: adding books and starting the program is faster when the Tag browser is hidden.
When PDFsam Basic or Mp3tag fits better
calibre is a single-purpose tool for e-books, and its 229.1 MB install is sizable for that. If your real task is splitting or merging PDF files, PDFsam Basic from the alternatives list is closer to the job. If you mainly tidy tags on audio files, Mp3tag fits better.
What's new in 9.17.0
Version 9.17.0 adds JPEG XL image reading and CSS Level 4 selector support in conversion, and speeds up MOBI, AZW3 and PDB output. It also fixes regressions that broke some PDF conversions and produced invalid EPUB 3 navigation markup.
calibre pros and cons
Pros
- Free, with a GPL-3.0 license
- Views, converts, edits and catalogs e-books in the major formats
- Fetches book metadata from the internet
- Can download newspapers and convert them into e-books
- Runs on Linux, Windows and macOS
Cons
- The 229.1 MB download is large for a single-purpose tool
- Interface is hard to judge before installing
- Google Play rating and install figures do not apply, since this is a Windows app
Is calibre safe?
The download link points to download.calibre-ebook.com, the developer's own server, and nothing is stored on our side. Kovid Goyal maintains calibre under the GPL-3.0 license. Run a scan on the installer before opening it, as you would with any program you fetch.
How to install calibre
- Press the download button to get the official file.
- Run the installer you saved and confirm the Windows security prompt if the publisher matches.
- Follow the setup steps, then start calibre from the Start menu.
