Amazon's flawed conversion of epubs

[NullNix]

Originally Posted by DNSB

Send to Kindle or email to Kindle do not support KF8/azw3 format. If you take a look at Learn About Sending Documents to Your Kindle Library, you won't find it on the list of supported formats. If you send an epub/docx/rtf/html, it will be converted to KF8/azw3 if the device it's sent to supports that format, for devices that don't support KF8/azw3, you will get a mobi format ebook.

Yes, but what they do support is 'dual MOBI', which is a file that contains both MOBI and AZW3 (so, as usual, JSWolf's conspiracy-theorizing is wrong and AZW3 works perfectly well if you do it right). They do this so that both old Kindles with no AZW3 support and new ones both get the format they prefer. The dual form is never sent to the Kindle but is always stripped down to the one format that particular Kindle would prefer. Calibre has long supported this.

[Quoth]

Originally Posted by NullNix

Yes, but what they do support is 'dual MOBI', which is a file that contains both MOBI and AZW3 (so, as usual, JSWolf's conspiracy-theorizing is wrong and AZW3 works perfectly well if you do it right). They do this so that both old Kindles with no AZW3 support and new ones both get the format they prefer. The dual form is never sent to the Kindle but is always stripped down to the one format that particular Kindle would prefer. Calibre has long supported this.

No doubt they will ditch Dual Mobi. AFAIK it's never worked for KDP. Send to Kindle is getting more like KDP now that web page has been added. No doubt they will limit to doc, docx, PDF and epub.

[DNSB]

Originally Posted by NullNix

Yes, but what they do support is 'dual MOBI', which is a file that contains both MOBI and AZW3 (so, as usual, JSWolf's conspiracy-theorizing is wrong and AZW3 works perfectly well if you do it right). They do this so that both old Kindles with no AZW3 support and new ones both get the format they prefer. The dual form is never sent to the Kindle but is always stripped down to the one format that particular Kindle would prefer. Calibre has long supported this.

Interesting. I tried sending a dual mobi a while back and got the support for mobi is going away message in response. I just tried using Send to Kindle for Web and a dual mobi could not be sent.

[Quoth]

Originally Posted by DNSB

Interesting. I tried sending a dual mobi a while back and got the support for mobi is going away message in response. I just tried using Send to Kindle for Web and a dual mobi could not be sent.

I expected that.
So the only uses for dual mobi is content you created either for download from your own website or upload to Smashwords as well as an ePub. Smashwords only redistributes the epub.
Your own or family/friend kindle doesn't need dual, either azw3 (or KFX) for most kindles or old mobi /KF7 for KK2, DX, DXG and original Kindle.

[Little.Egret]

Originally Posted by DNSB

Interesting. I tried sending a dual mobi a while back and got the support for mobi is going away message in response. I just tried using Send to Kindle for Web and a dual mobi could not be sent.

It might be worth trying renaming a dual mobi file as type .TXT and then using Send to Kindle. Same for azw4

[hleo12]

Originally Posted by Little.Egret

It might be worth trying renaming a dual mobi file as type .TXT and then using Send to Kindle. Same for azw4

I just tried this. Both my 10th gen and K4NT received the same AZW format. I guess Amazon is really done with mobi at this point.

[NullNix]

Originally Posted by Quoth

No doubt they will ditch Dual Mobi.

... presumably screwing up people who send periodicals at the same time. Oh well, I can always pull them in using the internal web browser. (As long as they don't drop mobi support from the firmware, and *that* is most unlikely given that they've never in the history of the Kindle dropped support for any formats.)

[A Lurker]

This debate has come full circle...

Amazon tries to prevent you from loading .awz3 files by blocking them from the sent-to-kindle email and app (which it appears you can get around by renaming the file extension .txt, but the point remains that they're actively trying to prevent you from sideloading .awz3 files). Why? Awz3 is the native format for Kindles. What motivation would they have to stop you?

This is why I believe @JSWolf might be on to something. He may not have it exactly right, but I suspect it has something to do with Amazons belief that only Amazon purchases are .awz3. They might believe that adding an non-purchased .awz4 is indicative of a bootleg.

[innocenat]

I believe the sole reason Amazon doesn't allow sending AZW3 is that Amazon don't have pipeline for converting AZW3 to other formats. Kindle iOS doesn't support AZW3.

[Quoth]

Originally Posted by A Lurker

This debate has come full circle...

Amazon tries to prevent you from loading .awz3 files by blocking them from the sent-to-kindle email and app (which it appears you can get around by renaming the file extension .txt, but the point remains that they're actively trying to prevent you from sideloading .awz3 files). Why? Awz3 is the native format for Kindles. What motivation would they have to stop you?

Amazon have many "Native" formats. Doc, docx and the preferred epub all convert to all of them. The epub is best. They don't accept ordinary mobi/KF7, azw3/KF8 or KFX for publishing.
They want to send KFX to apps, Fire and Whispernet.
Old Kindle eink and Kindle on iOS uses old mobi/KF7.
They also have fixed layout & periodical mobi for publishing.
There are some defunct formats.
The Kindle eInk, Fire and Apps can also display PDFs.

[tomsem]

Originally Posted by innocenat

I believe the sole reason Amazon doesn't allow sending AZW3 is that Amazon don't have pipeline for converting AZW3 to other formats. Kindle iOS doesn't support AZW3.

AZW3 is intended for side loading to Kindles and Fire tablets (usually with DRM), to support 'not connected to internet' use case. From Amazon's perspective, these books are already in your Kindle library, so there is no requirement to have Send To Kindle convert these for use as Personal Documents.

Amazon does not offer downloadable AZW3 for side loading to Kindle for iOS or Android, or the Mac/Windows apps, they assume these are connected to internet devices.

If you want to side load to iOS, you can use calibre KFX output plugin to convert from whatever format you have. Then you can use Finder (macOS) or iTunes (Windows) to side load the KFX file over USB or wirelessly to Kindle storage. I think PDF can be side loaded that way as well, not sure about other Kindle formats, but I'm guessing dual format MOBI would work, and maybe de-DRMed AZW3.

[Quoth]

If you want to side load on iOS use a real ePub app, not Kindle for iOS or Apple Books formerly iBooks. Same on Android.

[tomsem]

Originally Posted by Quoth

If you want to side load on iOS use a real ePub app, not Kindle for iOS or Apple Books formerly iBooks. Same on Android.

Sure, if you prefer (which you would). It's not something I do much myself, because I buy nearly everything from Amazon and it's already in the Kindle app. I was pointing out that it's possible to do so, and how to do it.

If you are a Mac and iOS person (as I am), the Books app is perfectly adequate and the most convenient thing at hand to read third party ePub on Apple devices.

As I'm currently far more committed to Kindle platform, I read with it only occasionally, but as it is, I don't feel the need to install third party ePub apps that won't sync with anything or whose developer abandons it, or I have to have it in DropBox just to start reading: I can just open it from wherever it is on my Mac (e.g. a calibre folder), and it's instantly available on all of my iDevices, without being crippled as Personal Documents are on Kindle. When I'm done reading, I can just delete it and it goes away on all of my iDevices (and from iCloud storage). You can also add and remove third party content via command line on a Mac. It's seamless.

A bonus is that it's literally the only iOS ePub reading app that properly supports Speak Screen (or for those who need it, VoiceOver and Voice Control). (Kindle is a close second.)

But yes, don't purchase any books from Apple.

If I still had Android devices (well I do but it's a POS), I'd probably go with Pocketbook app. It does TTS, syncs between devices/platforms, and works with cloud services, OPDS, as well as their own, and complements their worthy eReaders.

[MSWallack]

I sent several EPUB books to my Kindle (via Calibre). One was delivered just fine; the other was not delivered. I received an error email from Amazon telling me that I needed to use an acceptable format (EPUB, MOBI, etc.). Again, the book was in EPUB. So I used the Modify EPUB plugin to make the UTF-8 correction (just in case) and sent the book again. Same result. Any idea why this one particular book can't be successfully sent to my Kindle when it is in EPUB?

[innocenat]

The UTF-8 correction only fixed the weird character formatting problem. It won't fixed other errors.

Try doing an EPUB to EPUB conversion in calibre and send the resulting EPUB. If there are still error, you might want to try opening the EPUB in Kindle Previewer 3 to see what errors it show.