Convert files from and to KFX format online - AnyConv

Online KFX Converter

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What is a KFX file?

KFX is a proprietary eBook format developed by Amazon for its newer Kindle devices. It supports enhanced typography, better page layout, and advanced features like in-book progress tracking and word spacing adjustments.

Compared to older Kindle formats like MOBI and AZW3, KFX offers improved performance and readability. However, it is tightly integrated with Amazon’s DRM and delivery systems.

How to open KFX files

KFX files are used by newer Kindle devices and apps. They cannot be opened directly with standard tools, but Kindle Previewer and Kindle for PC/Mac support them.

If DRM-free, KFX files can be converted using Calibre (with plugins) or AnyConv to formats like EPUB or PDF.

Key facts about KFX

  • Full name: Kindle Format 10 (KFX)
  • Extension: .kfx
  • MIME type: application/vnd.amazon.mobi8-ebook
  • Developed by: Amazon
  • Initial release: 2015

Useful links and resources

Convert from KFX

FAQ

    👍 What is the best KFX converter?
    Perhaps our KFX converter is the best. AnyConv is fast, free and does not require software installation.
    🔺 How to convert eBook files to KFX?
    Choose files and upload them on the page. Select "to KFX" and click "Convert". After a few seconds, you can download KFX files.
    🔻 How do i change KFX to another format?
    Upload your KFX-file on the page. Select target format and click "Convert". KFX conversion takes a few seconds.
    📱 Can I use KFX converter on iPhone or iPad?
    Yes, you can convert KFX files from iPhone, iPad and other mobile devices, because AnyConv KFX Converter is a multi-platform web service.