It would be nice, if we would use the async Attribut for JS-Files <script src="demo_async.js" async></script>

[MacKP]

Here is an Example and an definition for it -> http://www.w3schools.com/tags/att_script_async.asp
Its usefull for all Modern Browsers and the older ones don't care about it.

regards

[leofeyer]

Not all scripts can be loaded asynchronically though. E.g. the media box relies on MooTools being loaded, which we cannot guarantee if the files are loaded asynchronically. We'll add an option in Contao 3.4 (see #7172) but we cannot just add the attribute everywhere.