What happens when you convert AZW3 to MOBI
- The AZW3 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.
- MOBI is an older Kindle format: Send to Kindle no longer accepts it, but older Kindles and the Kindle apps still read it. For a current Kindle, AZW3 or EPUB is the better choice.
- Books bought from Amazon usually carry DRM, which no honest converter removes. DRM-free books convert normally.
- 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 AZW3 to MOBI online
- Press "Choose AZW3 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 MOBI". 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 MOBI with its download button. Our server has already deleted both your AZW3 and the MOBI by then.
Why convert AZW3 to MOBI?
AZW3 files usually come from Kindle e-readers and books loaded onto them over USB. People convert them to MOBI because MOBI is what older Kindles and the Kindle apps read.
In short, AZW3 is good at what it was made for, and MOBI is the more practical choice when the file has to open, upload or print somewhere else. AZW3 opens on Kindle e-readers and in the Kindle and Calibre apps, while MOBI opens on older Kindles and in the Kindle and Calibre apps.
How to convert AZW3 to MOBI on Windows, Mac, iPhone and Android
On Windows
Open this page in Chrome, Edge or Firefox, drag your AZW3 files in from File Explorer, and press Convert. Each MOBI is saved to your Downloads folder.
On a Mac
Safari, Chrome and Firefox all work. Drag the AZW3 files from Finder onto the drop zone and the MOBI files land in Downloads.
On iPhone and iPad
Open the page in Safari and tap Choose AZW3 files. You can pick from Photos or from the Files app. The converted MOBI appears in Files, in the Downloads folder.
On Android
Open the page in Chrome, tap Choose AZW3 files and pick them from Files or your gallery. The MOBI is saved to the Download folder, where any file manager can find it.
Best settings for AZW3 to MOBI
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.
AZW3 vs MOBI: the differences
| AZW3 | MOBI | |
|---|---|---|
| Full name | Kindle Format 8 e-book | Mobipocket e-book |
| Type | e-book | e-book |
| Created by | Amazon | Mobipocket, later Amazon |
| First released | 2011 | 2000 |
| Compression | Lossless | Lossless |
| What it holds | a book's text, images, styling and table of contents | a book's text, images and table of contents |
| In a browser | opens on Kindle e-readers and in the Kindle and Calibre apps | opens on older Kindles and in the Kindle and Calibre apps |
| Common uses | Kindle e-readers and books loaded onto them over USB | older Kindle e-readers and e-books from the 2000s |
| MIME type | application/vnd.amazon.ebook | application/x-mobipocket-ebook |
About AZW3 and MOBI files
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.
What is a MOBI file?
MOBI was the Kindle's original format. Amazon has since moved to AZW3 and KFX and no longer accepts MOBI through Send to Kindle, which now takes EPUB instead.
AZW3 to MOBI 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 AZW3 to MOBI from the command line
This page uses Calibre. Installed on your computer, its ebook-convert command does the same conversion:
ebook-convert input.azw3 output.mobiConverting 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.
AZW3 to MOBI converter FAQ
Will I lose quality converting AZW3 to MOBI?
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 MOBI a different size from the AZW3?
The two formats store text and pictures differently, so the MOBI can be somewhat larger or smaller than the AZW3. Images are carried over as they are.
Are my AZW3 files uploaded?
Yes, for this conversion. A faithful AZW3 to MOBI 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 MOBI as soon as the result has been sent back to you. We do not keep, read or share it.
Can I convert several AZW3 files to MOBI 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 a MOBI file?
MOBI opens on older Kindles and in the Kindle and Calibre apps. MOBI is common for older Kindle e-readers and e-books from the 2000s.
Is this AZW3 to MOBI 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 AZW3 to MOBI 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 MOBI is saved to your Downloads folder.