Cache plugins play a significant role on your website. The caching plugins are not something, you install on your website and hope for the best performance.
In this post, we will test, analyze, and rank the top 6 WordPress cache plugin. Before we test the caching plugins, it’s important to know what is caching, and how it works.
What is Cache?
Before we get into the testing phase of our plugins, it’s important to know, what is cache in the first place.
A cache is something that is already stored for you. Let me explain this other way.
Did you ever notice that the site like YouTube, Facebook, and Amazon almost load instantly? Even though their web-pages are quite heavy.
Here’s a Google Page Speed Insights score for YouTube. According to that, it takes more than 8 seconds to load the first meaningful paint.
The question is, does YouTube really that long to load? Of-course not, and here’s why.
It has several MB’s of cache stored in your browser. And thanks to the cached data, when you visit the page next time it makes it load instantly.
How Cache can Help your website?
Caching can greatly boost website’s performance, and we’ll see how, in some simple points.
Boosting UX for your Website
When a user visit’s your website, and it loads super fast, the user will love that. And that user might convert into a paying customer in a long run.
And it’s the human psychology that, “If it’s Fast, it would be professional”.
In another way, for the decreased conversion rate, the poor UX or user experience can be the point to think of.
Think it that way, Amazon said, the 1-second increase in the load time, could make them potentially lose $1.6 Billion. Now, you know how important speed is for your website.
Caching Helps you with Search Engine Ranking
Google has stated that the user experience is one of the most important ranking factors for the websites. And if the user is happy with your site, and keeps visiting it again and again, it tells Google, this website is what the users love.
And happy users = Positive signal to Google = Higher Rankings in Search Engines.
About this Cache Plugin Test
For this post, I have thoroughly tested and analyzed 6 of the best WordPress cache plugins.
This study didn’t get sponsored by any of these plugins that I’m going to mention here. And neither did I get free access to any cache plugin.
So, I paid for all the plugins from my pocket and tested being as biased as possible.
Let’s take a quick look at the test website and then start testing our plugins.
Why you’ll not see a Mind-Blowing Performance increase?
My testing website is not like a traditional website for the testing.
I have already optimized my images. And all the other things, like hosting, theme, and plugins are also optimized.
That’s why I’m not using tons of high quality images (that would add up to a couple of MB’s).
And, sure if you reduce the image size, from 2 MB to 100 KB you see a massive performance boost. But that wouldn't be an honest review, right?
We will install WP Rocket as the first WordPress cache plugin. And we will record the performance for our website as we move forward.
The Website on which I’m Testing the Cache Plugins
I’m going to test the plugins on WPPedia. Becasue the website on which you will use the caching plugins will not be blank.
All of the readings will not be garbage, they are tested and recorded on a live functional website.
So, this is how our website looks at the time of creating this post.
And it will be similar to what most of us would be using.
I have 15 activated plugins at the time of testing on my website. It’s similar to what any comprehensive site would have.
But, before we begin the caching test, let’s first analyze our site with GT Metrix and Google Page speed insights.
GT Metrix Test for the website
I will run three different tests on my website to figure out the average score.
Let’s run the test, and see how our website is performing without the cache plugins.
The test server location is Vancouver, Canada, and from the Chrome browser.
Here’s the performance report for our website.
I’m using Cloudways Hosting Service for Digital Ocean Droplet, in case you’re wondering.
For the theme, I’m using Astra.
Now, this is the starting performance for our website. And, make sure you backup your website before using a caching plugin on your site.
About the Plugins Ranking
Before I test the plugins, I want to mention that their order doesn’t decide how good they are.
I’m picking the caching plugins randomly. And as I said, I’m running the test aside from any sponsorships as I’m purchasing the plugins that I test.
So, we will decide our winner at the end of our testing phase.
Now, let’s get into the actual testing process for our caching plugins.
1- Testing the WP-Rocket WordPress Cache Plugin
WP Rocket is one of the most famous website cache plugins I have ever used. And, in this post, we will test it to find, is it that good.
After you activate the WP Rocket plugin, you will see a new option in your Settings tab.
We can see a welcome message from WP Rocket on our dashboard.
Part (1)- Testing the site with Default WP Rocket Settings
Now, I want to leave to default, as any beginner would likely do. Then I will test my website’s score to see if we made any performance improvements.
When I test the website again with GT Metrix, I can see an almost 1-second drop in the load time.
That’s quite an improvement. The page size is still too heavy. So, I want to reduce the page size now.
Part (2)- Using the Advanced Settings of WP Rocket
Before we jumped into the advanced section, we tested our site with the default settings of WP Rocket.
Now, the first thing I want to go after is the Cache section of this plugin.
WP Rocket Cache Settings
We will look at the different cache settings and see if they work to increase our site performance.
If you have a membership website, you might want to serve the logged-in users with a cached feature.
File Optimization (For CSS, HTML, and Java)
It is where the magic happens. Like for more than 90% of the time, if you tweak the file optimization correctly, your site’s performance will increase.
Note: Be careful with what you do here. If you minify the CSS or Java, your site might break.
Imp-Point: Don’t change a ton of settings at once because if your site breaks, you will never understand what caused it. Always make one or two changes, and see if your site is okay?
I will minify the CSS, HTML, and Java. And then click on Save Changes.
Make sure you check your site thoroughly afterward. And if there’s something messed up, you can instantly revert your settings.
In this section, you can optimize your images for better performance.
Like Lazy Loading, it will load the images only once a user scrolls to that section. So, instead of loading the images all at once, the lazy loader will load them once they needed to.
I will enable the lazy loader for the images and click on save changes. You can also enable it for the iFrames and videos.
Testing the website with Advanced settings of WP Rocket
Now, I will retest the website with the advanced settings that we have used.
And, you can see an instant boost in the performance. The load time has dropped from 2.4 s to 2 seconds. The Page size has also reduced, with the total requests.
2- W3 Total Cache (Free Plugin)
W3 Total Cache is another free cache plugin that I have been using for a long time now.
It’s a free cache plugin, so anyone with a low budget can use this.
Testing the website without any Cache Plugin
Before we activate the cache plugin, I need a benchmark report. So, that we can track the performance as we move forward.
I ran the test 3 times so that I can get an average to get started.
And, this is the result I got. The performance is too bad, and we’ll try to make it better.
Now, I will set up a cache plugin and see if we improve any performance.
Set Up W3 Total Cache
Search for W3 Total Cache, install and activate the plugin.
Part (1)- Testing the Website with Default W3 Total Cache Settings
Like we did before, I will test the site with the default settings of the plugin. It is what most of us would be doing.
Let’s see how our site performs with the default settings.
So, this is quite surprising. The performance did improve a lot. And, the LCP decreased by almost 200 MS.
Part (2)- Testing the Performance with Advanced W3 Total Cache Settings
Let’s see if we improve our performance if we apply any advanced settings of W3.
I will first enable the Page Cache and Minify settings for HTML, CSS, and Java.
Make sure you check your website frontend, as it might break your site.
Minify HTML, CSS, and Java
In the minify section of the plugin. I will turn on the minify settings for HTML, CSS, and Java.
I’m not gonna go too deep in the advanced section. Because it’s where most of the people would go, and we’re simply testing the plugins.
Testing the Website with Advanced Settings
Let’s test our website after we applied the advanced settings of the plugin.
I will again test my website with GT Metrix and see how we improved. And, we did improve our performance a lot.
So, overall we reduced the LCP to around 500 MS, and we improved the Grade.
3- Autoptimize (Free Plugin)
The another cache plugin on our list is Autoptimize. It’s a free plugin so anyone with the low budget can follow up easily.
And, I’m going to do the same thing, that I did before. I will run the test with the default Autoptimize plugin settings.
Part (1)- Testing the Website with the Default WordPress Autoptimize Settings
Let’s test the website, with the default settings of the Auoptimize plugin.
You can see the LCP is quite good. But the grade isn’t that appreciable.
Let’s use some advanced settings, and see if we made any performance improvements.
Part (2)- Testing the Performance with Advanced Autoptmize Settings
Let’s see if we improve the performance with the advanced settings. I will first tweak the cache settings.
JS, CSS, and HTML
And, once you’re done, click on save changes.
In this section, you can optimize all the images of your website. I will select both of these settings, Optimize Images and Lazy-load images. And, once you’re done click on save changes.
In the Critical CSS section, you can eliminate render blocking resources.
If you scroll down the page, you will see an option to enter the API key for the Critical CSS. And, to use these features you need an API key.
And, once done, you can click on save changes.
These are all the settings I will change for now, and see how we improved the performance.
Testing the Website with Advanced Settings
With the Autoptimize advanced setting applied, let’s see how our website is performing now.
So, the LCP reduced by almost 200 MS, and the Grades improved a lot.
4- WP Super Cache (Free Plugin)
WP Super Cache is another popular caching plugin, with 2 Million active installations. And, we will run the same tests with this caching plugin, as we did before.
After you activate the caching plugin, you will see an option for it in the settings tab.
Before we get into any of the advanced caching settings, we will test our site with the default WP Super Cache settings.
Part (1)- Testing the Website with the Default WP Super Cache Settings
I tested the website leaving the caching settings to default to see how much the performance is improved. And you will notice that by default the cache is disabled, so I will turn on the caching.
Now, we’re on the basic caching settings, and I will run the website test on GT Metrix, to see the performance score.
The grade has improved, and so does the other scores, like LCP has improved a lot.
Part (2)- Testing the Website with the Advanced WP Super Cache Settings
I will turn on some of the advanced caching options for the WP Super Cache plugin, and then retest the website to see how much performance is improved.
In advanced caching section of the plugin, I will enable the cache for all visitors, and click on save changes.
So, these are pretty much the settings, I would change for this caching plugin.
And, WP Super Cache doesn’t seem to be giving more control than other caching plugins, I have checked so far.
I ran the test again for the website, and this is what I got.
The performance did improved a little, and the LCP reduced to about 100 MS.
So, would I use it as an amazing caching plugin for my websites? Probably not.
5- WP Optimize (Premium Cache Plugin)
WP-Optimize is a premium caching plugin. Many of my friends have been using this plugin for a very long time now. And, WP-Optimize plugin developers do make some bold statements, about their caching plugin.
We will test this caching plugin like we did before, and then we’ll give the final remarks.
Part (1)- Testing the Website with the Default WP-Optimize Plugin Settings
I will first test the website with the default caching settings of the plugin, as we did before.
The caching is disabled by default, so I will enable the caching first.
And, here’s the test result.
The performance score did improve a little. LCP reduced around 200 MS.
Let’s apply the advanced caching settings, and see how much we improve the performance.
Part (2)- Testing the Website with the Advanced WP-Optimize Plugin Settings
Before, I enable the advanced caching options. First, I will enable the lazy load for the images, and iFrame.
Then, I will enable the page caching, and click on save changes. It will enable the basic page caching on your website.
I will also enable the preload settings of the plugin.
WP Optimize GZip compression is already enabled, if it’s not, you can enable it, from the GZip tab.
In the WP Optimize Static Header section, I will enable the minify option for the website.
These are all the advanced caching settings that we enabled on the WP Optimize. Let’s test our website with these advanced settings applied, and see if the performance is improved.
This is the GT Metrix test score for the website, with advanced WP Optimize settings.
Not so amazing results, I’d say. But still the performance did improved a little with this caching plugin.
6- Comet Cache (Free Plugin)
Comet Cache is a free caching plugin. And its developers claim that the only thing you would have to do, enable caching.
We will test the Comet Cache, and see if it comes out true what they claim.
The first thing you have to do after activating the plugin, is enable the caching from the basic settings.
Testing the Website With Comet Cache
Let’s test the website after we activate the caching option of the plugin.
And, here is the test report for the website.
Overall the performance increased. The LCP is reduced by 500 MS, and the other grades have been improved. But, I’m not so surprised with the results.
The other settings like, HTML compression, and CDN filter is available in the Pro version of Comet Cache. So, I’d say Comet Cache didn’t seem to be giving away a lot of caching power to the users, especially to the free users.
So, these are all the tests we conducted on the top WordPress cache plugins.
So, we have tested all the plugins one-by-one in two different phases. One, with the basic, default settings applied, and with the advanced settings of the caching plugin.
And, while browsing Google, I found a really good-looking graph on Athemes. I think I should embed their caching test graph on this post, as it will make it even more helpful for you.
And, by the way this graph will represent the score of 9 top caching plugins.
So, this was the complete test of the 6 top cache plugins for WordPress websites.
And, as I first said in the, let’s give the caching plugins ranking on the basis of their results.
WP Rocket (WINNER)
After I have tested this plugin, I can say it’s the best caching plugin so far. We have seen a lot of performance improvement with only the basic settings.
And, the performance boost with the WP Rocket optimal settings was quite surprising.
Info: And for the CDN, you can use the WP Rocket Cloudflare settings. As CDN can boost the performance of your website even more with caching.
So, Finally if I had to choose a cache plugin for my website I would go with the WP Rocket.
WP Rocket Alternative (My 2nd Choice)
WP Rocket alternative would be W3 Total Cache. As I have found it more powerful, than the other caching plugins.
W3 Total Cache did an amazing work by improving the website performance overall.
If I wanted to pick the best caching plugin for my websites, which is free I would go with W3 Total Cache. And, of course, if I’m ready to invest a little in my website, I would choose WP Rocket as the best caching plugin.