What do the eBook file types AZW, AZW3, KF8, KFX, .EPUB, .MOBI, etc mean?

What on earth are these filetypes? These are all eBook filetypes, most associated with Kindle files.

Here are the most common eBook filetypes:

ePub: .ePub is the most common “non-Amazon” eBook file format. It is the standard.

MOBI: Originally created for the MobiPocket way back in 2000, it’s the second most common eBook file format that’s not used on Amazon. Amazon bought the company, but has shut it down, although the .mobi file format lives on.

AZW and AZW3: These two are the original proprietary Amazon Kindle formats. Any eBook sold on Amazon before the introduction of their current format, the KFX, would of been in these formats. .AZW was the original back in 2007 with the release of the first Kindle, whereas .AZW3 was adopted in 2011.

KF8: Amazon eBook file format that was used on the Kindle Fire. .KF8 is still common.

KFX: Amazon’s current file format, very advanced and flexible. Proprietary.

IBA: .IBA is the iBooks Author eBook file format, it’s very similar to ePub, except it only works in iBooks Author.

LRS, LRF, and LRX: Sony’s old eBook formats, abandoned by Sony in favor of .ePubs.

DJVU: Popular with scientists, this format has extreme file compression.

LIT: Microsoft’s old proprietary eBook file format, abandoned.

RFT: Rich Text Format, the eBook format equivalent of textedit. Simple and no frills.

Leave a Comment