How to convert mobi books to ePub format?

And, what did I say? Asnlinkda askedhow to convert a mobi book into an epub book(not how to convert an epub in a mobi). I said him that he should use some thid party app (that produces epub books) and if it's necessary, to polish the resulting book mobi to ePub converter. I also say that he could use mobi to ePub converter but that I prefer to use the first method. So, I say that is preferable to use (if it were necessary)

The way I go from Mobi > ePub is to use Vibosoft ePub creator or iStonsoft mobi to epub converter to convert, use Modify ePub to put in the cover and then use Sigil to rename the files and clean up the code/CSS. I find that's the easiest way to do it.

Vibosoft ePub creator guide:

How to convert .mobi books to ePub format

iStonsoft mobi to epub converter app:

How to convert mobi to ePub file

To read mobi books on iPhone or iPad, you have to first convert mobi to epub format as iPhone, iPad doesn't accept mobi directly.

Some .mobi books -especially if they were generated with Kindlegen 2.x- have a .kf8 version AND an old .mobi version inside (all the more, files generated by the service of Kindle Direct Publishing, are .mobi files). When we use KindleUnpack to unpack that kind of files, then the KindleUnpack produces an .epub book -for the .kf8 part of the original mobi- and others files for the .mobi7 part. We must work in Sigil with the .epub generated from the .kf8 part. Of course, if the book is an old one (previous to .kf8/azw3) then things are more difficult. Still we can build an epub with the .html, .ncx and .opf generated by KindleUnpack and the epub will work in ADE but won't validate at Epubcheck. If we want to be more prolix, then as you say, we have to use a lot of regex to clean de .html and after that to write a css stylesheet, to convet mobi to epub, you have to try professional tool like: mobi to ePub converter.