Runtime of WebAssembly : A study into WebAssembly runtime

Abstract: WebAssembly is Assembly-like code that is created by compiling other languages into Wasm. The Wasm file can then be run on the web at near native speed. The objective of this study is to find how WebAssemblys runtime compares to JavaScript and native. The study will also see if different browsers impact WebAssembly runtime. To get the information two different methods were used. Firstly literature and articles were used to gather data on JavaScript and native runtime compared to WebAssembly. Secondly an empirical study was conducted to compare four different browsers WebAssembly runtime.  When comparing WebAssembly and JavaScript it was found that WebAssembly isn't always the fastest alternative due to many reasons but some major ones were how they were compiled and optimised.  When looking at WebAssembly compared to native we could clearly see that WebAssembly was slower. These slowdowns came primarily from the increase in code size but the virtual environment and security checks also contributed to this.  After the empirical study we could see some differences between browsers both in compilation speed and execution time. Between the chromium browsers the difference in execution time was very small and Firefox was always faster. But when looking at compilation time Chrome was faster with the other browsers having varying results. The research could conclude that WebAssembly can provide a useful boost to runtime on websites when used correctly. It is not something that is going to replace JavaScript but can be used together with it. We could also conclude that the user's choice of browser has a small impact on WebAssembly and can cause differences in runtime.