Ebooks come in two main types of file: ePub and Mobi.
If you buy your ebooks direct from the same company that made your reading device, such as Amazon, Apple, or Kobo, you never usually have to worry about which type of file you should download. They will usually automatically appear on your e-reader, mobile app, or tablet after you've bought them.
But if you want to buy ebooks from independent bookshops you'll need to know what format suits your device. Many independent shops will provide a selection of file types with every purchase, others will ask you to choose one particular format.
You'll usually have a choice between ePub or Mobi.
- If you have a Kindle, choose Mobi format
As well as its own Amazon-only format, the Kindle can also display Mobi books.
The file names end in.mobi - If you have any other reading device, choose ePub format
Almost every e-reader and e-book app, other than Kindle, can display ePub books.
The file names end in.epub
Note: From August 2022, Amazon's Send-to-Kindle service will no longer support Mobi files sent through it to your Kindle library. Instead it will support ePub files, which it will automatically convert to a Kindle-compatible format. You will still be able to sideload Mobi files to your Kindle over USB.
All ebook files you buy from independent bookshops need to be free of any DRM.