What is AZW?

AZW (Amazon Word) is Amazon's proprietary eBook format based on the MOBI format with added DRM (Digital Rights Management) protection. Used by the original Kindle, Kindle 2, Kindle DX, and Kindle Keyboard devices. AZW files are essentially MOBI files with Amazon's encryption scheme, preventing unauthorized copying and sharing. The format supports basic text formatting, images, bookmarks, and notes but lacks advanced features like fixed layouts.

AZW was Amazon's primary format from 2007-2011 for Kindle Store purchases. While largely superseded by AZW3 (KF8) which supports HTML5 and CSS3, older Kindle devices still use AZW. Users encounter AZW files when accessing older Kindle purchases or using legacy Kindle devices. Calibre can convert AZW to EPUB or PDF for reading on non-Kindle devices, though DRM-protected files require additional plugins.

Did you know? AZW is based on MOBI format that dates back to the year 2000!

History

Amazon adopted and modified the MOBI format for the Kindle launch, adding DRM to create the AZW format for their eBook ecosystem.

Key Milestones

  • 2007: Kindle launch with AZW format
  • 2009: Kindle 2 adoption
  • 2011: AZW3 (KF8) introduced
  • 2014: KFX format development
  • 2016: AZW phase-out begins
  • Present: Legacy format support

Key Features

Core Capabilities

  • DRM Protection: Amazon encryption
  • MOBI-Based: Proven format
  • Text Reflow: Adjustable font size
  • Bookmarks: Reader annotations
  • Images: Basic image support
  • Whispersync: Cross-device sync

Common Use Cases

Old Kindles

Early Kindle devices

Legacy Books

Old Kindle purchases

eBook Archives

Historical collections

Conversion

Format migration

Advantages

  • Native Kindle compatibility
  • DRM content protection
  • Whispersync integration
  • Small file sizes
  • Proven stability
  • Text reflow capability
  • Cross-device reading

Disadvantages

  • Obsolete format (replaced by AZW3)
  • DRM prevents portability
  • Limited formatting options
  • Amazon ecosystem only
  • No fixed layouts
  • Basic typography

Technical Information

Format Specifications

Specification Details
File Extension .azw
MIME Type application/vnd.amazon.ebook
Base Format MOBI (Mobipocket)
DRM Amazon proprietary
Layout Reflowable text only
Status Legacy (superseded by AZW3)

Common Tools

  • Reading: Kindle devices, Kindle apps (iOS/Android)
  • Conversion: Calibre (with DeDRM plugin)
  • Management: Kindle for PC/Mac
  • Creation: Kindle Create, KindleGen (deprecated)