Evaluating a Web Tool for Smart Optimization of JavaScript Files

When a web page is displayed in a web browser, several files belonging to the web page are downloaded into the client’s device. The larger these files, the longer the browser will take to download and display the web pages. That is why optimizing the size of these files is important to improve the loading time of the web page and enhance user experience.On this work, we focus on the case of JavaScript, one of the most popular programming languages for building web pages. While the JavaScript files are getting larger, not all the downloaded code is necessary for the execution and display of a web page. In this context, we propose UFFServer, an online approach to optimize the size of the files required by a particular web application. UFFServer allows the identification and removal of functions based on monitoring web page usage. In this paper, we report on a controlled experiment that evaluates UFFServer. We evaluated UFFServer by analyzing the interaction of real users with 4 web pages for a time ranging between 2 to 10 months. We found that by using UFFServer the JavaScript files can be significant reduced.