Rocket Loader Update has slowed load speed dramatically


I’ve been trying to figure out the sudden speed decreases on a couple of client sites and finally realized that it was the result of Rocket Loader. I see now that there has been some type of update to it. I see it adds an ID tag to the scripts and then begins to load them one at a time VERY slowly where as before there would be 2-3 requests concatenating the js files.

Now once Rocket Loader begins processing JS files and downloading them, it takes an additional 2-4 seconds which slows the entire loading process of the page down.

One site went from an average load time of about 1 second fully loaded, to now almost 3 seconds with it active. If I turn Rocket Loader Off…it’s back down to 1.2 seconds.

Another site that used to load in about 1.4 seconds is at upwards of 4-5 seconds with it active.

Whatever was done has destroyed the benefit of Rocket Loader for every site I’ve tested it on that has the updated system.


It can be finicky. Can you send the URL for us to inspect?


@john18 that does not sound like normal behaviour - if you can share a URL here I’d be happy to take a look or drop a ticket into Support and ask them to send it to me.

The new version of Rocket Loader defers the loading of Javascript but does not load 3rd party scripts via your Cloudflare domain - it’s possible that’s the source of the slow down but I suspect there’s something else unusual happening here.


I’ll have to either setup a test domain or find a time to switch it back on temporarily as it was causing too much of a slowdown for my clients’ sites to leave it active. I’ve got a staging domain already setup for one of them so I may activate it for that subdomain and see if I get the same behavior, if I do I’ll post the URL here.

I’ve never run into this type of an issue and I’ve been using Cloudflare for over 3 years and Rocket Loader for the majority of that time across multiple sites.The sites are on different hosts, all are Wordpress based, but are using different themes, etc, plugins, some using caching, some not, etc.

It’s like night and day compared to what it used to be prior to the update (I won’t use the word upgrade at this point).


@john18 you don’t need to re-enable the feature - we can test internally without impacting your production traffic. So when you have a moment drop a line to Support and mention this thread.


Closing this - we’re investigating this particular issue with @john18’s websites.

closed #7