That night, the code was pushed to a public branch. Within days, players were running modded 1.12 worlds on school Chromebooks, fighting the Ender Dragon with zero lag spikes.
After weeks of patching, a breakthrough: the first stable 1.12.2 survival world running entirely in Wasm GC mode. Chunk loading was snappy. Entity AI computed faster. And the memory footprint? Down 30% — because Wasm GC structs are far more compact than JS objects. eaglercraft 1.12 wasm gc
Here’s an informative story about and its experimental Wasm GC backend. In a dimly lit server room, a developer named Alex stared at a browser tab. Running Minecraft 1.12.2 — complete with Forge mods, redstone contraptions, and shaders — inside a vanilla browser. No plugins. No native code. Just JavaScript and WebAssembly. That night, the code was pushed to a public branch
Alex grinned. Eaglercraft 1.12 with Wasm GC wasn’t just a tech demo. It proved that full legacy Minecraft could live forever, directly in browsers, with near-native performance — no plugins, no downloads, no Java runtime. Chunk loading was snappy
And the browser’s garbage collector just hummed along, quietly collecting fallen leaves in the background.
WebAssembly Garbage Collection is a new proposal that allows compiled languages (Java, C#, Kotlin) to manage memory using the browser’s built-in GC, rather than emulating it in JavaScript or manually managing linear memory. For Eaglercraft, this was revolutionary.
Eaglercraft had already pulled off the impossible: a full Java-to-JavaScript recompilation of the Minecraft client using TeaVM, plus a custom WebSocket-based multiplayer protocol. It ran in any modern browser, no installation needed. But version 1.12 was a beast — over 8 million lines of Minecraft code, plus the labyrinthine complexity of the 1.12.2 engine. Performance stuttered. Garbage collection froze the screen mid-PvP.