Codename One

Codename One is a mobile first toolkit designed for building high-quality, cross-platform native apps for Android, iOS, Desktop & Web. According to the vendor, it enables developers to write code once and run it on multiple platforms, eliminating the need for separate codebases. Codename One is suitable for companies of all sizes and is used by mobile app developers, software engineers, IT professionals, entrepreneurs, and startups across various industries.

Key Features

Native Performance: Codename One compiles Java or Kotlin into native code for iOS, UWP (Universal Windows Platform), Android, and even JavaScript. The vendor claims that this ensures optimal performance and allows apps to leverage platform-specific capabilities.

Extensible: Codename One offers a wide range of native and generic add-on libraries/plugins (cn1libs). These libraries, developed by both Codename One and the community, provide additional functionality to apps without requiring developers to start from scratch.

Hot Reload: According to the vendor, developers can make changes to the Java or Kotlin source code and see the immediate impact in the running app within the Codename One simulator, without the need to restart the app.

CSS Live Update: The vendor states that changes made to the app's CSS stylesheet, such as theme, images, or fonts, are instantly reflected in the Codename One simulator, allowing developers to experiment and visualize different styles.

Established & Mature: Codename One has been in the market since 2012 and has gained the trust of developers and enterprises. With a community of over 40,000 developers and approximately 180 million app installations across platforms, Codename One is considered a stable and reliable platform for building mobile apps.

Free & Open Source: The core of Codename One is released under the GPL + CE licenses, providing developers with the freedom to use it for commercial projects without any licensing fees.

Pixel Perfect Design: Codename One provides a rich set of widgets specifically designed for mobile apps. These widgets offer a native look and feel by default and can be further customized using CSS to achieve unique designs.

Developer-friendly Tooling: Codename One allows developers to write, debug, and test apps directly within their preferred IDE (IntelliJ, Eclipse, VSCode, or NetBeans) using the Codename One simulator. The vendor emphasizes the ease of use and the availability of one-click builds for app-store-ready devices.

One Codebase, Multiple Apps: Codename One enables rapid cross-platform app development using Java or Kotlin with 100% code reuse. Developers can build their apps once and deploy them on Android, iOS, Desktop, and Web platforms, reducing the effort required to maintain separate codebases.