Note though that the blogpost is 5 months old, and the comparison is out of date. For example, as also noted in other comments, Emscripten can handle memory as

Note though that the blogpost is 5 months old, and the comparison is out of date. For example, as also noted in other comments, Emscripten can handle memory as either 1. Singleton fixed typed array (what most users use; the fastest) 2. Singleton growable typed array (aka asm.js memory growth; still not optimized in all browsers, though) 3. Split memory, in which each chunk of memory can be allocated separately, which allows fully dynamic memory usage the way C and C++ do natively (allocating and freeing pages to the OS), https://github.com/kripken/emscripten/wiki/Split-Memory https://github.com/kripken/emscripten/wiki/Split-Memory (but the flexibility makes it harder for JS engines to optimize)