Comparing the Energy Efficiency of WebAssembly and JavaScript in Web Applications on Android Mobile Devices

Context. WebAssembly was created as an alternative to JavaScript for developing heavy loading web applications. Since JavaScript is known to have long execution times. A lot of research is already performed to compare the run-time performance of WebAssembly against that of JavaScript. However, little research is available that compares the energy consumption of WebAssembly versus JavaScript. Goal. With this study we aim to identify the correlation between the energy consumption and the use of WebAssembly versus JavaScript. This will aid developers in deciding which method matches the needs of their project best in terms of energy efficiency. Method. The subjects of the experiment are WebAssembly and JavaScript. During the experiment two research questions are defined. For the first research question the programming language is the independent variable. For the second research question the web browser is the independent variable. For both research questions is the energy consumption of the Android device in Joules the dependent variable. Results. We can confirm that the energy consumption of WebAssembly is less than that of JavaScript. The browser also plays a role since the energy consumption of Firefox is significantly smaller than that of Chrome for both WebAssembly and JavaScript. Conclusions. This study provides evidence that using WebAssembly for the development of web applications can reduce the energy consumption and thus improve the battery life of a user's Android device. Developers can use this information when choosing a programming language to develop a web application. Moreover, using Firefox over Chrome does also reduce the energy consumption of web applications developed both with WebAssembly and JavaScript.