MOBI – Mobipocket

What is a MOBI File?

Founded in 2000, Mobipocket SA, a French company, pioneered the .mobi e-book format and developed Mobipocket Reader software. It catered to mobiles, PDAs, and desktops. Mobipocket's free suite encompassed tools for various devices like Kindle, iLiad, and Symbian. Amazon acquired it in 2005 and operated it till 2016.

This e-book format offers features like adjustable text size, fonts, bookmarks, and annotations. MOBI files can also include images and tables, making them suitable for displaying complex content. While they were commonly used for Kindle e-readers, the landscape has changed over time.

Current Usage

The MOBI format can still be found on third-party download sites, but it has been replaced by Amazon's proprietary AZW3 format. This format, developed in-house by Amazon, is essentially an upgraded version of MOBI with enhanced DRM capabilities, updated layouts, and typesetting.

Because MOBI's primary focus was Amazon device compatibility, files were often larger than their EPUB counterparts. However, as Kindle devices now support EPUB format, the dynamics have shifted. EPUB's smaller file sizes and broader compatibility have made it a more favorable choice.

With Kindle now supporting EPUB, MOBI's importance has decreased. If you come across a MOBI file, it's usually wise to convert it to EPUB, AZW3 or PDF.

Find out how to: Convert EPUB, MOBI, AZW to PDF format using PDF2Go.