eBooks are non-editable and reflowable books that are converted to digital eBook formats and can be read on any digital device, such as a computer, tablet, or Mobile.
Below is the list of most commonly used eBook formats:
- EPUB – EPUBs are the most widely used file format for eBooks. Developed by the International Digital Publications Forum (IDPF), it replaced the old Open Electronic Book (OEB) format in 2007. EPUB is an open standard defined, free to use, and is vendor-independent, it has become the most common EBook format. While not often seen, it can even support colour images, SVG graphics, interactive elements, and videos.
- To some extent, EBook is similar to MP3 which can be played onto any music player, Almost all EReaders and computer operating systems support the format, Publishers can also incorporate it into any DRM system of their choice.
- Disadvantage – Amazon Kindle devices cannot read it (with the exception of the Kindle Fire tablet), so if you have an EPUB format book that you want to read on your Kindle device, you can use Caliber to convert EBooks to another format.
- MOBI file is also known as the MobiPocket EBook file, it was invented by a French company MobiPocket as an EBook format, the file extension was original with .prc and later changed to .mobi, Initially, It was introduced by MobiPocket in the year 2000 as a format for distribution of EBooks as reflowable text on devices of different sizes like Mobile and eReaders, later in the Year 2005, MobiPocket was acquired by Amazon.
- Amazon launched the Kindle in 2007 and continued to use the format with the .mobi extension and was the primary source of uploading EBooks for publishing through Amazon until 2017 later Amazon launched a new tool “Kindle Create” for EBook publishing service.
- Disadvantage – MOBI is not an open standard, it is not available publically, it doesn’t support audio and video, Except Barnes and Noble NOOK, it supports all the major eReaders.
- AZW and AZW3 – The AZW and AZW3 extensions are two proprietary EBook formats from Amazon. AZW is the oldest of the two; and was released in 2007 along with the first Kindle, whereas AZW3 was introduced along with Kindle Fire reader in 2011.
- AZW3 has more advanced features than AZW. It supports more styles, fonts, and layouts. Although it’s never been officially confirmed, AZW and AZW3 format are similar to the MOBI format, Android, IOS and popular EBook management apps like Calibre and Alfa can read AZW and AZW3 format.
- Disadvantage – AZW and AZW3 formats do not support video and audio. Since AZW and AZW3 are proprietary formats they are not supported widely on EReaders as compared to EPUB and MOBI. NOOK and KOBO EReaders cannot read the AZW and AZW3 format.
- IBA – IBA is the format used for books that specifically creates Apple’s iBook Author app, technically the format is as similar as EPUB format, The IBA format supports video, sound, images, and interactive elements.
- Disadvantage – IBA format is only used for books written in iBooks Author, It cannot be read in all EReaders as it depends entirely on the custom widget code in the Apple Book app.
- PDF – PDF format is widely adopted around the web, It is the most popular way of delivering eBooks, it’s the only second format on the list that’s an open standard, it became ISO 32000 back in 2008.
- Disadvantage – A major drawback of this format is it lacks native reflowing, it just cannot adapt its presentation according to the screen size.