Add your files
Drop one MOBI or two hundred. Batch conversion is not a paid feature here.
An old Kindle-format book has to be read on a Kobo, in Apple Books, or in any reader that is not Amazon's.
The Mobipocket structure is rebuilt as EPUB: HTML sections, a proper spine, and a navigation document. The result reflows properly and works in every modern reader.
MOBI files bought from Amazon carry DRM, and those cannot be converted. Only files that were DRM-free to begin with, such as sideloaded books or ones from publishers who sell without it, will convert at all.
The conversion fails immediately rather than producing a bad result. Books bought from the Kindle Store are protected.
It will not get worse, and EPUB can express more than MOBI could. But the conversion cannot restore styling that MOBI discarded when the book was made.
Drop one MOBI or two hundred. Batch conversion is not a paid feature here.
EPUB Ebook is lossless, so nothing is thrown away in the conversion.
Converted and deleted the moment it finishes. Never written to permanent storage.