For quite some time now, Amazon has been signalling that in August 2022, they will be discontinuing Send to Kindle support for MOBI files. They will be supporting Send to Kindle for EPUB files instead.
You can read about the details of how Amazon itself supports sending documents on their Personal Documents help page here:
So, going forward, starting on Monday, July 25, when someone uses Leanpub's own convenient Send to Kindle feature, we will be sending the EPUB file for the Leanpub book. People who buy and read Leanpub ebooks will probably not notice any difference at all.
The tl;dr message here is that, if you'll pardon an indirect pun, the writing is on the wall for the MOBI format.
While we have always supported the MOBI format in the past, Amazon has actually been discouraging MOBI use for a while now. From the publisher's (and self-published author's) side of things, you can see this in the difference between their EPUB and their MOBI guidance here:
Now, as this article states, "people will still be able to sideload MOBI books using a USB cable if they want to, but Amazon will no longer support that format as part of the Kindle Personal Documents Service so MOBI books will no longer be wirelessly delivered or added to your Kindle account for syncing and backup like they are now".
So while Amazon will still allow a clunky manual workaround to add MOBI files to Kindle, they are clearly sending the signal that they don't want people reading MOBI files.
You don't have to do too much reading between the lines to see that this means that in the future, they don't want publishers and self-published authors producing MOBI files, either.
As the article cited above also suggests:
"This will affect some smaller publishers that offer books for Kindles in MOBI format, but at least with the addition of ePub support people will still be able to easily send ebooks acquired from outside of Amazon using the Send to Kindle apps, provided the ePubs don’t have DRM, of course."
Given Amazon's clear signalling here, going forward, Leanpub will be discontinuing MOBI support for books generated using our own book generation workflows.
To be really clear ourselves: starting on Monday, July 25, whenever you generate a new preview or published version of your Leanpub book, you will no longer be generating MOBI files, either for the main book, or for the sample book, if you have one.
We're assuming that most authors who, up until this point, have been using Leanpub-generated MOBI files to publish their books on Amazon, will be able to just switch seamlessly to using their Leanpub-generated EPUB files instead.
This will probably be an improvement over uploading the old MOBI format: EPUB is just a better format for ebooks, including on Kindle, which is presumably why Amazon is going in this direction.
So, just like readers who use our own Send to Kindle feature to send their Leanpub books to Kindle won't notice this switch, we're hoping authors won't be affected in any practical way either: if you're publishing on Amazon, you can just validate and upload your Leanpub EPUB file using the same Kindle Previewer you were using for MOBI.
If you have any feedback or questions about this article, please email the Leanpub team about it at email@example.com!
If you have any questions or thoughts on writing and self-publishing with Leanpub, please join our global community of authors in our Authors Forum here!
Interested in creating your first Leanpub book? Here are some quick tutorials for our most popular writing modes: http://help.leanpub.com/en/articles/3088382-quick-walkthroughs-for-getting-started-on-a-leanpub-book
Are you looking for great deals on Leanpub ebooks, ebook bundles, and courses? Sign up for our Weekly and Monthly newsletter sales here!