Empowering Web Applications with WebAssembly: Are We There Yet?

WebAssembly is the newest web standard. It defines a compact bytecode format that allows it to be loaded and executed fast. While WebAssembly is generally believed to be faster than JavaScript, there have been inconsistent results when it comes to showing which code is faster. Unfortunately, insufficient study has been conducted to understand the performance benefits of WebAssembly. In this paper, we investigate how browser engines optimize WebAssembly execution in comparison to JavaScript. In particular, we measure their execution time and memory usage with diverse programs. Our results show that (1) JIT optimization in Chrome significantly impacts JavaScript speed but has no discernible effect on WebAssembly speed; (2) WebAssembly uses much more memory than JavaScript. We hope that our findings can help WebAssembly virtual machine developers uncover optimization opportunities.