  Leveraging JavaScript (JS) for User Interface (UI) interactivity has been the
norm on the web for many years. Yet, using JS increases bandwidth and battery
consumption as scripts need to be downloaded and processed by the browser.
Plus, client-side JS may expose visitors to security vulnerabilities such as
Cross-Site Scripting (XSS).This paper introduces a new server-side plugin,
called JSRehab, that automatically rewrites common web interface components by
alternatives that do not require any JavaScript (JS). The main objective of
JSRehab is to drastically reduce-and ultimately remove-the inclusion of JS in a
web page to improve its responsiveness and consume less resources. We report on
our implementation of JS-Rehab for Bootstrap, the most popular UI framework by
far, and evaluate it on a corpus of 100 webpages. We show through manual
validation that it is indeed possible to lower the dependencies of pages on JS
while keeping intact its interactivity and accessibility. We observe that
JSRehab brings energy savings of at least 5 % for the majority of web pages on
the tested devices, while introducing a median on-the-wire overhead of only 5 %
to the HTML payload.
