In the next major version update, 1.13.0 in May, which will follow 1.12.3 in March and 1.12.4 in April, we plan to remove support for the deprecated Collada format and asm.js as an HTML5 backend.
Collada
The Collada format is difficult to maintain, and adding new features requires significant effort. Existing Collada libraries have not been maintained for several years. In addition, Collada support has been removed from Blender 5.0 (deprecated in Blender 4.2). Because of this, we have decided to remove Collada model support in order to reduce maintenance burden and focus more effort on improving glTF support.
asm.js
According to Poki statistics Poki for Developers - Reach the world on web, WebAssembly is supported on 100% of devices playing games on their platform. According to CanIUse "wasm" | Can I use... Support tables for HTML5, CSS3, etc, WebAssembly support is at 95.89%.
Dropping asm.js will reduce maintenance effort and shorten CI build times, since asm.js is the slowest platform to build and maintain. WebAssembly support is already fragmented across different features and requires separate builds, for example for SIMD support or 64-bit value support.
Removing asm.js will also make it easier to plan and develop future HTML5 features without maintaining an additional target.
If you have projects that rely heavily on Collada, you still have time to migrate to glTF (glb). If something on our side blocks this migration, please create an issue and provide a repro project so we can fix it before the deadline.
If you have a project that still depends on asm.js, please provide more information about the platform, audience, and your use case. This will help us analyze the situation and decide whether reconsideration is necessary.