How Fast Is WebAssembly?

Jun 5, 2020 • Arne Vogel

This work is a summary of the paper “Not So Fast: Analyzing the Performance of WebAssembly vs. Native Code” by Abhinav Jangda, Bobby Powers, Emery D. Berger, and Arjun Guha


WebAssembly was introduced to be an efficient and fast alternative to JavaScript. The goal is to achieve execution times within the range of native code performance. But can WebAssembly achieve this goal? The original paper which introduced WebAssembly already tries to answer this question. But doubts have been expressed about the validity of the benchmarks used for this purpose.

This paper explores how fast WebAssembly is compared to native code. For this purpose new benchmarks of WebAssembly and native code are evaluated. Furthermore, the reasons for WebAssembly’s slow execution speed are examined, and whether these reasons can be alleviated in the future is discussed.