Discover unused CSS Selectors with Helium

Helium is a javascript tool for discovering unused CSS selectors across multiple pages on a web site and it runs from the browser.


Add a script element somewhere on your site that is loaded into every page that will be tested. This is typically a header or footer section. The element looks like:

<script type="text/javascript" src="path/to/helium.js"></script>

Helium is initiated by calling the method “helium.init()”. This has to be placed somewhere on the page where it gets called after page load. An example of this is:

<script type="text/javascript">
    window.addEventListener('load', function(){


    }, false);