Step 1: Supply your EPUB files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted AZW3 files.
EPUB to AZW3 Conversion FAQ
What does the EPUB to AZW3 converter do?
+
It converts a EPUB file into AZW3 format. AZW3 is Kindle Format 8, which Amazon introduced in 2011 to replace the ageing MOBI format.
Will the data inside my EPUB be preserved when converting to AZW3?
+
Yes — the content is mapped to the AZW3 equivalent. Format-specific extras that AZW3 does not represent natively are omitted rather than corrupted.
Is the EPUB to AZW3 conversion reversible?
+
You can convert the AZW3 back to EPUB on this site. If either format involved is lossy, the round-trip is not bit-perfect even though it is visually or audibly close.
What output quality should I expect from EPUB to AZW3?
+
Default settings target broadcast / web quality — visually identical to the source for most viewers. For archival use, pick the highest quality option in the converter settings.
Why does my EPUB file refuse to convert?
+
DRM, in almost every case. A protected EPUB is encrypted and tied to an account, and no converter can decrypt it — ours included. Files you created yourself, or bought from a DRM-free store, convert without any trouble at all. EPUB has no fixed pagination, so page numbers are meaningless, and complex layout — tables, equations, multi-column — degrades badly.
Is there a file-size limit when converting EPUB to AZW3?
+
Free conversions have a size limit per file, set by the type of file, and the page tells you when a file is over it. A paid plan removes that limit, so much larger files can be converted.
Can I batch-convert several EPUB files to AZW3 at once?
+
Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
What happens to my EPUB files after the conversion?
+
Uploaded files are processed on our own conversion servers, nobody looks at them, and they are not shared. The upload and the converted file are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
Where can I open my AZW3 file?
+
AZW3 opens in the standard tools for its category. Browsers and built-in OS viewers handle the common cases.
Do I need to install software to convert EPUB to AZW3?
+
No. The converter runs entirely in your browser plus our cloud — no plugin, no install, no admin rights. It works on Windows, macOS, Linux, ChromeOS, iOS, and Android.
Do I need an account to convert EPUB to AZW3?
+
Yes. One conversion an hour is free, with no account needed, for a file within the free size limit. A paid plan removes the hourly limit and the size limit, and lets you add several files to one job.
Is there an API for EPUB to AZW3 conversion?
+
Yes. Every conversion this site offers is also exposed via a JSON API — see /api/ for endpoints, authentication, and rate limits. EPUB to AZW3 is one of the supported pairs.
