Companies Using Cloudflare Rocket Loader

Mostly small sites behind Cloudflare: 58.58% of matched companies with a known size have 1 to 10 employees. Large organisations use it too. WSP, Leidos, Elsevier, Expeditors and Ogilvy served Rocket Loader's markup on their main sites when we checked on 14 November 2026, and Garmin and Harley-Davidson run it on single subdomains. Only 43.83% of the domains are WordPress.

We count 152,136 domains with Rocket Loader on in our November 2026 crawl, after removing 8,889 for-sale, parked, placeholder and duplicate domains. They are domains, not customers: Rocket Loader is a free setting on every Cloudflare plan. 77,698 match a company. Since 16 March 2026, 74,360 domains stopped showing it on every hostname we saw.

Rocket Loader holds 1.13% of Performance Optimization at TechnologyChecker.io, 4th of 45 rows. Priority Hints leads with 91.95%, but it's a browser attribute, not a product. Autoptimize (1.76%) and WP Fastest Cache (1.55%) are WordPress plugins above it, and EWWW Image Optimizer follows at 0.98%. Rocket Loader is the first row that works at the network edge.

Anything that controls when scripts run. HTML's own defer and async attributes do it per script. On WordPress, Perfmatters (39,150 domains in our crawl) delays JavaScript, and FlyingPress defers what can wait as part of a paid caching plugin. Autoptimize (236,271) and WP Fastest Cache (207,566) are larger, but they mainly minify and cache, so many sites run them alongside Rocket Loader.

The United States, with 20,872 of the 77,698 companies we matched, then the United Kingdom (7,079), India (4,741), Brazil (4,626) and Canada (3,093). Those five hold 52.01% of matched companies. Germany is 10th with 1,539, behind France, Turkey and Spain, and Saudi Arabia (1,029) and the United Arab Emirates (878) are in the top 15.

Small ones, mostly. 58.58% of matched companies with a known size have 1 to 10 employees and 25.64% have 11 to 50. 1,162 have more than 1,000 staff, including WSP, Leidos and Expeditors on their main sites. A setting that costs nothing on Cloudflare's Free plan reaches every size of company that sits behind Cloudflare.

Mostly founded since 2000. Of matched companies with a founding year, 43.6% started in the 2010s, 18.56% in the 2000s and 18.26% in the 2020s. 19.58% predate 2000, a group that includes Elsevier (1880), Toll Group (1888), Smithfield Foods (1936) and WSP (1959), all of which served Rocket Loader on 14 November 2026.

On our data: a company with 1 to 10 staff, founded in the 2010s, in IT services, retail or software, based in the US, UK, India or Brazil, with its site behind Cloudflare (98.78% of domains) and jQuery on the page (67.82%). Someone on that team has opened the Cloudflare dashboard's Speed settings and turned the switch on.

In the Cloudflare dashboard, go to Speed, then Settings, then Content Optimization, and switch the Rocket Loader toggle off. With the API, send a PATCH request to the zone's rocket_loader setting with the value "off". To change it for some hostnames only, Cloudflare's docs point to a configuration rule instead of the zone-wide toggle.

It defers the loading of a page's JavaScript until after the content has rendered, according to Cloudflare's docs. It handles inline and external scripts and keeps their order, and Cloudflare turns it off for browsers it detects as incompatible. The aim is earlier first paint and first contentful paint on pages with a lot of JavaScript.

Yes. Cloudflare's docs list Rocket Loader as available on the Free, Pro, Business and Enterprise plans. It is off by default: Cloudflare's API schema gives the rocket_loader setting a default value of "off", so every one of the 152,136 domains we count had someone turn it on.

Add data-cfasync="false" to that script tag. Cloudflare's docs say Rocket Loader then ignores it and still optimises the other scripts on the page, and that any scripts it depends on need the same attribute. If the problem is limited to one page, the docs suggest a configuration rule that excludes that URL.

View the page source. Look for a script loading /cdn-cgi/scripts/.../cloudflare-static/rocket-loader.min.js with a data-cf-settings attribute, script tags whose type reads like a code followed by -text/javascript, or inline handlers starting "if (!window.__cfRLUnblockHandlers) return false;". All 34 live matches in our 14 November sample showed the loader script.

It can. Cloudflare's docs say that if you see JavaScript or jQuery issues, you should disable Rocket Loader and retest, and that a Content Security Policy needs updating to allow it. jQuery is on 67.82% of the domains we count, so the conflict risk applies to most of this list.