KaiOS

KaiOS is a Linux-based mobile operating system for feature phones that is derived from Mozilla's Firefox OS. It is designed to bring smartphone-like functionality to devices with limited hardware and traditional keypad input, by running lightweight web applications built with HTML5, CSS, and JavaScript.

The OS emphasizes a compact, web-centric runtime and is optimized for low-cost devices with modest memory and processing power. It supports modern connectivity such as 4G LTE and VoLTE, as well as Wi-Fi, Bluetooth, GPS, and expandable storage. KaiOS devices generally feature physical keypads or small touchscreens and are intended to deliver essential apps without requiring a full smartphone.

App ecosystem and user experience: KaiStore, the official app store, hosts applications built with standard web technologies. Notable apps that have been available on KaiOS include messaging, social media, and media apps such as WhatsApp, Facebook, YouTube, and various Google services in selected markets. In some regions, KaiOS devices also offer integration with voice assistants and native features through partnerships with service providers.

History and market presence: KaiOS Technologies released KaiOS in 2017 as a fork of Firefox OS. It targets emerging markets where affordable 4G feature phones are in demand. The platform powers popular devices such as the Nokia 8110 4G and the JioPhone family in India, among others. Through collaborations with manufacturers, operators, and Google, KaiOS positions itself as a bridging platform between traditional feature phones and smartphones, continually updating the OS with new features and language support.