After receiving feedback from our users, we’re announcing that in our next update, Vellum will return to generating mobi files for the Kindle platform.

Vellum recently moved away from creating files in the mobi format, as the KindleGen utility that Vellum used to convert these files is not compatible with the forthcoming version of macOS. To generate mobi files in a manner that works with macOS Catalina, Vellum will switch to use conversion tools bundled with Amazon’s Kindle Previewer utility.

Because we have also received some positive feedback about the new Kindle.epub files, generating Kindle-specific EPUB will remain as an option. This option will also serve as a fallback in case the conversion tools in Kindle Previewer fail in the future.

This update is currently planned for October 2. In the meantime, if you need to convert Kindle.epub files to the mobi format, you can do so by opening your file in Kindle Previewer and using the Export option. If you have any questions, please contact us.