Defold is a lightweight 2D game engine that was originally developed internally at King (the Candy Crush studio) before being released to the public and eventually handed over to the independent Defold Foundation in 2020. The engine is completely free with no royalties, no subscription fees, and no revenue sharing.
King built Defold because it needed a fast, efficient engine optimized for the kinds of 2D games that the mobile market demanded. The engine uses Lua as its scripting language, which is clean, easy to learn, and performs well on mobile devices. The editor runs on Windows, macOS, and Linux, and games can be exported to iOS, Android, HTML5, Windows, macOS, and Linux.
Defold’s standout feature is its tiny build sizes. A basic Defold game can compile to just a few megabytes, which matters enormously for mobile distribution and web games where download size directly impacts player conversion. The engine achieves this through a component-based architecture that only includes what the game actually uses.
The Defold Foundation, supported by donations from King and other sponsors, oversees the engine’s development and ensures it remains free forever. The source code is available on GitHub under a custom license, and the community contributes extensions, asset libraries, and native plugins.
The engine includes a visual editor with a scene graph, animation tools, particle effects, physics (via Box2D), a built-in profiler, and hot-reload for rapid iteration. Native extensions allow developers to integrate platform-specific features like ads, analytics, and push notifications.
Defold hasn’t produced the same headline-grabbing indie hits as GameMaker or Godot, but it’s found a solid niche in mobile game development, web gaming, and situations where performance on low-end devices matters. Several studios use it for production mobile titles, particularly in markets where older devices are common.
