The File Extensions Database


.MOBI File Extension

  • Developer by: Amazon
  • Category: eBook Files
  • Format: Binary

What is an .MOBI file?

.MOBI is Mobipocket eBook

A MOBI file is an eBook saved in the MOBI format, a format originally used by the Mobipocket Reader but now supported by several different readers. It contains an eBook and may incorporate DRM copyright protection to prevent copying or unauthorized viewing. MOBI files are supported by various eReaders, tablets, PDAs, and desktop computer applications.

Amazon's new Kindle Format 8 (KF8) is based on the MOBI format. KF8 supports many new formatting and layout options, including HTML5 and CSS3 content and embedded fonts. KF8-formatted eBooks are saved and distributed as ".mobi" files or as .AZW3 files, depending on the device that downloads the eBook. eBook authors can compile KF8 books using Amazon's KingleGen software. Before distribution, authors can preview KF8 eBooks on a Mac or PC with Amazon's Kindle Previewer software.

Amazon now owns the MOBI format. Amazon's eBook formats, including .AZW, .AZW1, and AZW3, use the MOBI format but incorporate a proprietary DRM scheme.

NOTE: Mobipocket eBooks also use the .PRC extension.

Programs that open Mobipocket eBook
Windows
Amazon Kindle for PC
Amazon Kindle Previewer
Calibre
Geometer Plus FBReader
BookDesigner
Cool Reader
MBP reader
Icecream Ebook Reader
Mac
Amazon Kindle for Mac
Amazon Kindle Previewer
Calibre
Geometer Plus FBReader
PatiSoftware theLibrarian
Linux
Calibre
Geometer Plus FBReader
Cool Reader
MBP reader
Android
Cool Reader

How to solve problems with MOBI files

  • Associate the MOBI file extension with the correct application. On :
    Windows: Right click on any MOBI file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.MOBI files". Mac: Right click (or Ctrl-click) the MOBI file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .MOBI is Mobipocket eBook. Because only the current version supports the latest MOBI file format. Search, therefore, e.g. on the Amazon manufacturer website after an available .MOBI is Mobipocket eBook update.
  • To make sure that your MOBI file is not corrupted or virus-infected, get the file again and scan it with antivirus software.