FileHint
JAEN

.mobi

Low risk

Mobipocket E-book

The early Amazon Kindle e-book format. Amazon has since moved on to AZW3 and KFX; MOBI is legacy.

MIME types

  • application/x-mobipocket-ebook

Category

document

Aliases

.prc

What opens this file

  • Kindle app
  • Calibre
  • FBReader

How to open by OS

Windows

  • Kindle for PC, Calibre.

Mac

  • Kindle for Mac, Calibre.

Linux

  • Calibre, FBReader.

Ios

  • Kindle, Marvin.

Android

  • Kindle, FBReader.

Safety notes

  • Older Calibre builds had CVEs in the MOBI parser; keep Calibre up to date.

Common mistakes

  • Amazon stopped accepting MOBI via Send to Kindle in 2022; EPUBs you send are now auto-converted to KFX.
  • When hand-authoring MOBI, preview in Kindle Previewer before distribution to catch layout bugs.

Related extensions

References