What's KaiOS?

KaiOS is a web-based mobile operating system that enables a new category of smart feature phones. It is forked from B2G (Boot to Gecko), a successor of the discontinued Firefox OS.

KaiOS brings support of 4G/LTE, GPS, and Wi-Fi, as well as HTML5-based apps and longer battery life, to non-touch devices. It has an optimized user interface for smart feature phones, needs little memory, and consumes less energy than other operating systems. It also comes with the KaiStore, which enables users to download applications in categories like social media, games, navigation, and streaming entertainment.

KaiOS logo


  • KaiOS developer's guide

    Official KaiOS documentation which explains how KaiOS is built, provides usage examples and contains essential technical knowledge.

  • KaiOS UI CSS

    Kick off development of your KaiOS app with native components thanks to @canicjusz.

  • KaiOS training

    Get hands-on experience with developing KaiOS apps with our courses. Learn how to build, test and deploy KaiOS apps.


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