Not So Fast: Analyzing the Performance of WebAssembly vs. Native Code

WebAssembly is a new low-level programming language, supported by all major browsers, that complements JavaScript and is designed to provide performance parity with native code. We developed Browsix-Wasm, a "UNIX kernel in a web page" that works on unmodified browsers and supports programs compiled to WebAssembly. Using Browsix-Wasm, we ran the SPEC CPU benchmarks in the browser and investigated the performance of WebAssembly in detail.