Convert EPUB to AZW3.
Turn a DRM-free EPUB into AZW3, the Kindle KF8 format, to copy onto a Kindle over USB with its styling intact.
AZW3 or MOBI?
AZW3 (KF8) is the newer Kindle format and supports far more of EPUB's styling, such as fonts, floats and better tables. Choose it over MOBI for any Kindle from the last decade.
Sideloading
Plug the Kindle into a computer, copy the AZW3 into its documents folder and the book appears in the library.
Size change
An AZW3 is usually a little larger than the EPUB, because the Kindle format stores some data in more than one form.
How it works
- 01
Upload your EPUB
Drop a file or pick one from your device. Private by default.
- 02
Convert with Calibre
Calibre rebuilds the book as a Kindle KF8 (AZW3) file.
- 03
Download
Grab your AZW3.
Native Kindle format with rich styling
Chapters and table of contents kept
Private uploads, auto-deleted after 1 hour
No watermark, no signup to try
Open-source Calibre engine
EPUB to AZW3
This re-flows the book into AZW3, carrying chapters, the table of contents and images. Reflowable ebook formats adapt to the reader's screen and font size. Heavy fixed layouts (comics, textbooks) convert less cleanly.
Common questions
Is it free?+
Yes. Convert EPUB to AZW3 free. No signup and no watermark. Free covers 10 server conversions a day, up to 100 MB a file. Pro removes the daily limit and raises the file limit to 2 GB.
Is my file private?+
Your file is uploaded to a private bucket, converted on our own engine, and auto-deleted after 1 hour. It is never sent to a third-party converter.
Do I need AZW3 for Send to Kindle?+
No. Send to Kindle accepts EPUB directly. AZW3 is useful when you copy books to a Kindle over USB, where EPUB is not readable.
Can it convert store-bought books?+
Only DRM-free EPUBs. Books protected by DRM are encrypted and cannot be converted by FileWhirl or any legitimate converter.
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