Converted to .azw3 - but KDP won't accept?

[Austruck]

Howdy! I just used Calibre to convert an author friend's Word doc to .azw3 so it'll be readable on Kindles. And it looks amazing.

BUT, Amazon/KDP is telling her that it cannot process her file. This makes no sense to me, since most of the Kindle books I've bought directly through Amazon are in .azw3 format. And of course, the file looks perfect on both of our Kindles. (I have a first-gen Paperwhite, if that matters.)

What are we doing wrong, that KDP/Amazon doesn't like the file?

[eschwartz]

Well, if it looks good on your Kindle, it must be good everywhere, right?

Wrong!
For one thing, AZW3 doesn't have a MOBI fallback for older devices, which Amazon mandates support for.
Amazon supports Kindles going all the way back to the very first model -- and the Kindle 2 and Kindle DX don't support AZW3 either, nor does the Kindle Keyboard without a firmware update that some people might not have. Amazon will not allow you to sell a book that won't be able to be downloaded on those devices.

If you are selling through the KDP, you should probably use kindlegen to convert.
Use calibre's Editor to import your DOCX, save as EPUB and make sure it looks good. When you're happy with it, use kindlegen/Kindle Previewer to turn the EPUB into an Amazon-blessed dual-MOBI.


Amazon has been known to reject calibre-converted MOBIs when it detects that calibre was used to convert it.

[Austruck]

Strange that so many of the books I've purchased through Amazon (from big publishers and indie authors) have been in .azw3 format.

I chose that over .mobi because the .mobi conversion was giving me an extra blank page or two between chapters.

I'm unsure how Amazon could tell if I've created a file through Calibre. Plus, all four of my own books for sale on Amazon were created via Calibre, with no issues from Amazon. Same with most of my author friends.

Will check out Kindlegen. Thanks for the tip! Publishing's like navigating hostile waters sometimes!

[eschwartz]

Originally Posted by Austruck

Strange that so many of the books I've purchased through Amazon (from big publishers and indie authors) have been in .azw3 format.

I chose that over .mobi because the .mobi conversion was giving me an extra blank page or two between chapters.

Correct. kindlegen creates a "dual-MOBI" which contains an AZW3 section and a MOBI section.
Amazon demands a MOBI section at a minimum, in order to support old devices.
I am pretty sure you can upload *just* a MOBI and they will accept it (to stay compatible with mobipocket creator), but if you want AZW3 as well...

The dual-format file will be split by Amazon and they will only send AZW3 if your device supports AZW3 (but if your device only supports MOBI, they will send the MOBI).

I'm unsure how Amazon could tell if I've created a file through Calibre. Plus, all four of my own books for sale on Amazon were created via Calibre, with no issues from Amazon. Same with most of my author friends.

Will check out Kindlegen. Thanks for the tip! Publishing's like navigating hostile waters sometimes!

calibre has a unique conversion style.
Plus it leaves "creator" metadata.

Anyway, the reports are inconsistent, and IIRC plain MOBI was always OK even if calibre created it.
But plain MOBI is legacy garbage.