Making WebAssembly even faster: Firefox’s new streaming and tiering compiler

People call WebAssembly a game changer because it makes it possible to run code on the web faster. Some speedups are already present, and some are yet to come. With streaming compilation, the browser compiles the code while the code is still being downloaded. Up until now, this was just a potential future speedup. But with the release of Firefox 58 next week, it becomes a reality. Firefox 58 also includes a new 2-tiered compiler. The new baseline compiler compiles code 10–15 times faster than the optimizing compiler. Combined, these two changes mean we compile code faster than it comes in from the network.