Shrinking WebAssembly and JavaScript code sizes in Emscripten Emscripten is a compiler toolchain for asm.js and WebAssembly which lets you run C and C++ on the web at near-native speed. Emscripten output sizes have decreased a lot recently, especially for smaller programs. For example, here’s a little C code: #include <emscripten.h> EMSCRIPTEN_KEEPALIVE int add(int x, int y) { return x + y; } This