AZW3 → EPUB
Unpack a KF8 file into standard EPUB so it opens in Apple Books, Kobo, Calibre or anything else. DRM-free files only.
Drop your AZW3
or click to choose — the only ceiling is your own memory, none on our side
AZW3 files hold KF8, the format Amazon introduced in 2011 to replace the ageing MOBI. The interesting part for anyone converting one is where KF8 came from: Amazon built it on EPUB. Underneath the Palm database wrapper is markup with real CSS, proper headings and the kind of styling MOBI never supported.
That makes this conversion unusually clean. Unwrapping a KF8 file recovers markup very close to what the publisher originally supplied, which is why AZW3 to EPUB loses less than almost any other format pairing here — second only to EPUB to HTML, where nothing is translated at all.
The reason to do it is portability. An .azw3 opens on a Kindle and in Calibre and essentially nowhere else. The same book as an EPUB opens in Apple Books, Kobo, Google Play Books, Thorium, every browser-based reader, and Kindle itself through Send to Kindle. As always, this only works on files without DRM.
Format by format
| What it does | AZW3 | EPUB |
|---|---|---|
| Introduced | 2011, as Amazon's KF8 | 2007, by the IDPF; now at the W3C |
| Built on | EPUB, wrapped in a Palm database container | Itself — it is the standard |
| Styling | Full CSS, close to EPUB's | Full CSS |
| Opens in | Kindle and Calibre | Apple Books, Kobo, Google Play Books, Calibre, Kindle via Send to Kindle |
| Ownership | Amazon proprietary | An open standard anyone can implement |
| Conversion loss to the other | — | Minimal, because they share a lineage |
What actually changes
KF8 was built from EPUB and then packed into Amazon's Palm database container. Unwrapping it recovers markup very close to the original, which makes this one of the cleanest conversions on the site.
What survives
What does not
How it works
KF8 is detected automatically, including inside combo files that carry both MOBI and KF8.
Each section becomes a document, decompressed and parsed on your own machine.
Standard, portable, and readable everywhere.
FAQ
No. Purchased books carry DRM and are locked to your account. This tool cannot open them and removing DRM is not something we support. It works on DRM-free files: your own writing, Project Gutenberg, Standard Ebooks, indie publishers and bundle sites.
MOBI is the older format, from 2000, with very limited formatting. AZW3 carries KF8, introduced in 2011 and built on EPUB, which supports full CSS. Both sit inside the same Palm database container and both are unpacked by the same reader here.
Barely. Because KF8 is derived from EPUB, most of the original markup survives the round trip — more than any other format pairing on this site apart from EPUB to HTML, where no translation happens at all.
Ambiguous extension: some .azw files are MOBI inside, some are KF8. Drop it here and the reader works out which it is; if it turns out to be MOBI, the MOBI tool is the more natural door but the result is the same.
Calibre opens it, but Apple Books, Kobo, Google Play Books and most browser readers do not. Converting once gives you a file that opens everywhere instead of one that needs a specific application.
Yes. The whole conversion runs on the phone, and a typical novel finishes in a few seconds. Very large illustrated books are the case where memory becomes the limit.
DualBook translates the whole book and gives you the original alongside it.
