How To Batch Convert Mobi To Epub For Novel Collections?

A while ago my friend gave me a Kindle but since then I have changed to Kobo and therefore I needed to convert my ‘mobi’-files. First I tried ‘Calibre’ (very reliable, but for 100+ files way too slow), then I also tested ‘CloudConvert’ (online, mostly free but very limited free tier) and in the end I went for ‘Any eBook Converter’ (paid but fast as hell).

'Calibre' is probably the best converter for the average user. It's a free open-source app you can download and add your mobi files to. Then just select convert and choose your desired output settings (e.g. disable heuristic processing to prevent unusual line breaks, and enable keep cover to keep your covers). For comics and illustrated novels, select 'no processing' to keep images intact.

For fan-translated light novels (and other niche stuff), be sure to verify any footnotes afterwards, I lost some translator notes to silly linebreaks by skipping the preview. Rename files systematically when converting (i.e. use Title_Author.epub instead of whatever ‘random-number.mp3’-like nonsense you were using before). It’s kind of a chore, but it’s totally worth it when you’re unable to sleep at 2AM and need to find That One Light Novel Volume 3.

So, for bulk conversions, I rely on Calibre (obviously!) but have also explored some of the other options. Online Convert is okay for small numbers of e-books but is far too slow for large numbers, whilst KindleUnpack and Sigil can be used to extract the ‘mobi’ content and then re-package it into an ‘epub’ file, which is great for Windows users.

For the more tech-savvy amongst you, it’s also possible to script the conversion using Python and the EbookLib library – I’ve managed to convert 500 novels overnight to throw at Amazon using this method. For those without programming skills, there’s also the paid option of Epubor Ultimate which is very user-friendly and allows for batch conversion of ebooks in a simple drag-and-drop interface. Just remember to always backup your originals before attempting to convert in bulk, as I learned the hard way when half my batch converted to rubbish!

A minor aside re: metadata: epub better preserves the author/title sort than mobi, which is important if you have a massive 2,000-book collection like I do.

For years I’ve been accumulating e-books and in order to keep my e-book library in sync, I need to convert them from ‘mobi’ to ‘epub’. There’s a wonderful piece of software called ‘Calibre’ which is completely free. This can handle conversions in batches, and therefore makes perfect sense for me to add all of the ‘mobi’ files that I have to Calibre, select them all, and then convert them to ‘epub’. It does work, but sometimes the output files can be a bit quirky, particularly with long novels. I convert in batches of around 20-30 e-books at a time in order to avoid putting too much pressure on the software. Note also that, in order to convert DRM-protected e-books, you need to first remove the DRM using something like ‘DeDRM’.