What happens when you convert EPUB to AZW3
- The EPUB is converted by Calibre, the widely used open-source e-book manager, on our conversion server.
- Chapters, headings, images, the cover and the table of contents are carried over, and the text still reflows to fit any screen, because both formats are e-book formats.
- This conversion runs on our server: the file is uploaded, converted, and deleted together with the result as soon as the result has been sent back to you. Nothing is kept. Files up to 25 MB are accepted.
How to convert EPUB to AZW3 online
- Press "Choose EPUB files" and select one or more files, or drag them onto the box. Files up to 25 MB each can be converted.
- There are no settings to choose: the converter keeps everything the target format can hold.
- Press "Convert to AZW3". The file is uploaded to our conversion server, converted in a few seconds, and deleted together with the result as soon as the result is sent back.
- Save each AZW3 with its download button. Our server has already deleted both your EPUB and the AZW3 by then.
Why convert EPUB to AZW3?
EPUB files usually come from e-books from stores other than Amazon and free e-book libraries. People convert them to AZW3 because AZW3 is the Kindle's own modern format, the one to copy onto a Kindle over USB.
In short, EPUB is good at what it was made for, and AZW3 is the more practical choice when the file has to open, upload or print somewhere else. EPUB opens in Apple Books, Google Play Books, Kobo and most e-reader apps; a Kindle needs it sent through Send to Kindle, while AZW3 opens on Kindle e-readers and in the Kindle and Calibre apps.
How to convert EPUB to AZW3 on Windows, Mac, iPhone and Android
On Windows
Open this page in Chrome, Edge or Firefox, drag your EPUB files in from File Explorer, and press Convert. Each AZW3 is saved to your Downloads folder.
On a Mac
Safari, Chrome and Firefox all work. Drag the EPUB files from Finder onto the drop zone and the AZW3 files land in Downloads.
On iPhone and iPad
Open the page in Safari and tap Choose EPUB files. You can pick from Photos or from the Files app. The converted AZW3 appears in Files, in the Downloads folder.
On Android
Open the page in Chrome, tap Choose EPUB files and pick them from Files or your gallery. The AZW3 is saved to the Download folder, where any file manager can find it.
Best settings for EPUB to AZW3
There are no settings: Calibre keeps the book's own styling, cover and table of contents, and the reading app decides the font size.
DRM-protected books cannot be converted. Books from Project Gutenberg, Standard Ebooks, public libraries' free collections and most independent authors are DRM-free.
EPUB vs AZW3: the differences
| EPUB | AZW3 | |
|---|---|---|
| Full name | Electronic publication | Kindle Format 8 e-book |
| Type | document | e-book |
| Created by | the International Digital Publishing Forum | Amazon |
| First released | 2007 | 2011 |
| Compression | Lossless | Lossless |
| What it holds | chapters as XHTML pages, with images and a table of contents | a book's text, images, styling and table of contents |
| In a browser | opens in Apple Books, Google Play Books, Kobo and most e-reader apps; a Kindle needs it sent through Send to Kindle | opens on Kindle e-readers and in the Kindle and Calibre apps |
| Common uses | e-books from stores other than Amazon and free e-book libraries | Kindle e-readers and books loaded onto them over USB |
| MIME type | application/epub+zip | application/vnd.amazon.ebook |
About EPUB and AZW3 files
What is an EPUB file?
An EPUB is a ZIP archive of web pages, one per chapter, plus a file that lists their order. That is why its text can be extracted with ordinary web tools.
What is an AZW3 file?
AZW3, also called KF8, is the Kindle format that supports modern styling. Books bought from Amazon usually carry DRM, which no honest converter can remove; DRM-free AZW3 files convert normally.
EPUB to AZW3 not working? Common problems
- "Files up to 25 MB can be converted." Server conversions have a size limit. Compress the images in the document, or split it, and try again.
- "The conversion took too long and was stopped." Very long or complex documents can exceed the time limit. Split the document and convert the parts.
- The e-book will not convert. Books with DRM, usually those bought from Amazon or other stores, are encrypted and cannot be converted.
Convert EPUB to AZW3 from the command line
This page uses Calibre. Installed on your computer, its ebook-convert command does the same conversion:
ebook-convert input.epub output.azw3Converting on your own computer keeps the file entirely local, which is worth it for very large or very sensitive documents. For everything else, the converter on this page does it without installing anything.
EPUB to AZW3 converter FAQ
Will I lose quality converting EPUB to AZW3?
The text, images and structure are kept, and the book still reflows to fit any screen, because both are e-book formats.
Why is the AZW3 a different size from the EPUB?
The two formats store text and pictures differently, so the AZW3 can be somewhat larger or smaller than the EPUB. Images are carried over as they are.
Are my EPUB files uploaded?
Yes, for this conversion. A faithful EPUB to AZW3 conversion needs Calibre, the open-source e-book manager, which cannot run in a browser. The file travels over an encrypted connection, is converted in a private temporary folder, and is deleted together with the AZW3 as soon as the result has been sent back to you. We do not keep, read or share it.
Can I convert several EPUB files to AZW3 at once?
Yes. Select or drop as many files as you like; they are converted one after another and each gets its own download button.
How do I open an AZW3 file?
AZW3 opens on Kindle e-readers and in the Kindle and Calibre apps. AZW3 is common for Kindle e-readers and books loaded onto them over USB.
Is this EPUB to AZW3 converter free?
Yes. There is no sign-up and no watermark. Because this conversion uses our server, there is a fair-use limit of 25 MB per file and a number of files per hour, which stops the service being overloaded.
Can I convert EPUB to AZW3 on my phone?
Yes. It works in Safari on iPhone and iPad and in Chrome on Android. The conversion happens on our server, so it is as fast on a phone as on a computer; the AZW3 is saved to your Downloads folder.