User blog comment:DaNASCAT/Technical Update: August 26, 2015/@comment-24473195-20150826194015/@comment-24473195-20150828130420

Another suggestion would actually be taking it to another level and having something like opting in to custom js:


 * Anonymous users / registered users must opt-in to custom js


 * Admins can opt-out if they like

The bottom line is that many/most wikis serve huge javascript pages to all users. Increasing the page load time for someone that doesn't need it. Regardless of whether someone is just reading/ editing. In some cases this may be useful, but in others it can be disastrous. For example, some wikis contain broken js that causes the visual editor to stop loading:


 * http://community.wikia.com/wiki/Thread:896482


 * Forum:Can't edit pages on my Wiki. Stuck on "Loading editor"


 * https://www.mediawiki.org/wiki/Talk:VisualEditor#Is_VisualEditor_broken_in_eswiki.3F