WP Rocket – The best settings

The settings of WPRocket haven't changed much over the years, considering they've only released one new feature since 2020.

WP Rocket/RocketCDN struggles with LCP, TTFB, and mobile performance optimization. Preloading images in viewable area isn't supported for LCP, and the feature for stripping unused CSS is slower than other plugins because it loads the used CSS inline. RocketCDN simply serves files from StackPath's CDN, without comprehensive page caching, image resizing for mobile, and other essential features. Since TTFB accounts for 40% of LCP, many WP Rocket users report issues.

Cache settings

There are cases where you should disable WP Rocket’s page caching.

• If your host uses caching (or Full Page Cache from Cloudflare)
• If you use the following plugin: Great Page Cache for Cloudflare.
• If you use another cache plugin

WP Rocket has specific instructions and helper plugins for using NGINX + Varnish, such as the NGINX helper plugin when NGINX caching is enabled and using custom Varnish IP addresses.

File optimizations

For most pages, Minify CSS/JS should be enabled, but Combine CSS/JS should be disabled. Defer/Delay JavaScript should both be enabled and can improve several PageSpeed recommendations.

Minify CSS/JS files: To – Leave it off if you're using Perfmatters to remove unused CSS. Minifying files removes whitespace from code and reduces file sizes. If you're using Cloudflare's APO, Cloudflare recommends using WP Rocket for minification and leaving Cloudflare's minification settings OFF.

Combine CSS/JS files: Out of This setting won't work if "Delay JavaScript Execution" is enabled. WP Johnny also explains why you shouldn't combine CSS/JS files, especially for sites with large CSS/JS files (which you can check in your GTmetrix waterfall chart). Combining CSS/JS files can also cause problems when using HTTP/2 and HTTP/3 servers. For all these reasons, you should leave this setting disabled.

Excluded CSS/JS files: If enabling a minify setting breaks your website, look at the source code, find the problematic file, and add it here. See the post by WPRocket to fix minification issues.

Optimizing CSS delivery: Remove unused CSS—omit it if you're using Perfmatters to remove unused CSS. Even after WP Rocket reworked this in version 3.11, used CSS continues to load inline. While this is better for scores, it's slower for users because the file can't be cached and increases HTML size. Even Perfmatters' documentation states that inline is better for PageSpeed scores, while a "separate file" is better for perceived performance. FlyingPress, Perfmatters, and LiteSpeed Cache all load used CSS in an external file, while WP Rocket is the only caching plugin I know of that loads it inline.

Delayed loading of JavaScript: To – Loads JavaScript after the page has finished parsing and eliminates render-blocking resources in PSI. If you continue to see render-blocking issues, you can try installing Async JavaScript alongside WP Rocket and then enabling "Apply Defer" in the settings.

Delay JavaScript execution: To – Reduces third-party code by delaying JavaScript until user interaction (like scrolling or touching the screen on mobile). If this breaks your site, review WP Rocket's compatibility exclusions and exclude any plugins/themes/services from the delay.

media

In the Media tab of WP Rocket, it is recommended to activate all available optionsto optimize your website's loading times and improve the user experience. By enabling image optimization, you can ensure that your images load in the best possible quality while maintaining a compact file size. You should also enable the option for CSS background images to improve the display of your website. It is also a good idea to enable these settings for iFrames and videos, especially from platforms like YouTube, as they increase page loading speed and overall performance. These measures not only improve visibility in search engines but also increase visitor satisfaction.

You can also make exceptions – but they are usually not necessary.

Fill cache

Here, too, you can activate all options. Exception: Your hoster is too weak.

database

The "Database" section of WP Rocket gives you the option to clean up your database. Feel free to enable all options here.

Heartbeat

What is Heartbeat?

The Heartbeat feature in WP Rocket offers the ability to optimize the interaction between the server and the browser by adjusting the frequency of the Heartbeat API. This API allows WordPress to transmit important information in real time, such as auto-save drafts and user activity in the backend. By adjusting the heartbeat frequency, website owners can use server resources more efficiently and improve their site's performance, especially on high-traffic websites. A reduced frequency of heartbeat requests can help speed up load times and improve the overall user experience, while reducing the risk of server overload. With this feature, users have control over an often overlooked but crucial component of WordPress performance.

CDN settings

A CDN, which stands for “Content Delivery Network,” is a network of servers located in different locations around the world.

The main function of a CDN is to deliver web pages and other content (such as images, videos, or files) to users faster. When you visit a website, the content is often loaded from a server near you. This makes the website faster because the data doesn't have to travel as far.

Imagine you order a package. If it comes from a warehouse near you, you'll receive it faster than if it comes from a warehouse far away. That's how a CDN works: It helps deliver the content to you faster and more efficiently.

A CDN (Content Delivery Network) is useful when people from different countries visit your website. For example, if your website is located in Germany and most of your visitors come from Germany, a CDN is probably not necessary.

If you use Cloudflare, you can simply forget about this tab. If not, configure everything here as described in your CDN's instructions.

Is WP Rocket recommended?

It depends on. I think other caching plugins are better than WP Rocket. The only advantage of WP Rocket is that it's very quick to set up. Alternatives like FlyingPress or Litespeed have more features, are often faster, and offer more options.

If you want, you can browse all the WordPress cache plugins I recommend here:

That's it. Feel free to ask any questions!