Planned Deprecation Notice: MOBI exports

Last year, Amazon announced that they were discontinuing their KindleGen command line tool that Pressbooks uses to generate MOBI files, and recommended that users use EPUB format for publishing new reflowable titles and updating previously published titles in the Kindle ecosystem.

Because the tool we use to generate MOBI files is no longer supported, and Amazon suggests delivering EPUBs into their ecosystem, we have decided to remove support for MOBI exports from the Pressbooks platform in a forthcoming release.

Going forward, our flowable ebook export efforts will focus exclusively on the EPUB format. Users who still wish to produce MOBI files for personal use will be encouraged to generate these files using Pressbooks EPUB exports and freely available desktop applications like Kindle Previewer or Calibre.

If you’re interested in tracking the progress of this task, please see this GitHub issue: Retire MOBI exports · Issue #2193 · pressbooks/pressbooks · GitHub

FYI, MOBI exports will be removed from Pressbooks core in our next release of Pressbooks (5.25.0), which is scheduled for release this week. Amazon’s KDP now recommends uploading EPUB files to their service anyway, but if you’re interested in producing MOBI files to sideload on your own Kindle devices, you should be able to do this on your own computer using the instructions provided by Kindle Previewer: Kindle Previewer or Calibre: E-book conversion — calibre 5.23.0 documentation, two free desktop applications which can convert EPUB files to the MOBI format.

The most recent release of Pressbooks (Release Pressbooks 5.25.0 · pressbooks/pressbooks · GitHub) removed the option to produce MOBI exports. Please see earlier posts in this thread or Goodbye, MOBI Exports! - #5 for additional details.