Top WordPress Caching Plugins Head-to-Head Tests

I tested 7 of the top WordPress cache plugins. There were 3 clear winners. See which plugins came out ahead and why. Plus, discover the 3 things you have to know about the test conditions to achieve similar results for your site.

About this post

Last Update: 4/26/17 W3TC has a lot of super nice features, including settings for HTTPS. But, the plugin has been unstable for over a year. I can no longer recommend it, no matter how well it performs.

This is a brief of my test results because I realize most of you just want to know which plugins I recommend.

My Webmaster Level 5 members will receive:

• the full 149 page report
• 2 spreadsheets of all data collected
• plugin tweaks and recommended settings
• host environment specifics

3 things you HAVE to know about caching tests

Caching plugins speed up your site. You need one to achieve top performance.

There are three super important factors you have to match to get the same results on your site that are shown in these tests.

1. Your host server type matters.

In fact, it matters more than anything else as to whether you will get the biggest benefit from your caching plugin. I tested these plugins on both Litespeed and Apache servers.

2. Plugin settings matter.

All 7 of the plugins I tested required tweaking the settings a bit.

That included turning some of them on!!!!

So, if you’ve installed a plugin and never touched the settings, you probably aren’t getting as much benefit, if any, as you could.

3. Amount of traffic matters.

Caching needs to be set differently around a break point of above and below 10,000 visitors/day.

My tests were conducted on shared servers and the plugins were set for an average of 5,000 visitors/day.

Your results will vary if you don’t have the same setup as I have in these test conditions.

The plugins can be tweaked to suit your needs, so you are not limited to only these test conditions.

Hosting Conditions

I ran two sets of tests on two different host server types, both on shared hosting plans.

They are:

• LiteSpeed – has 2 types of server-side caching built in
• Apache – has no server-side caching
• Apache with ngnix – proxy server in front of Apache

The winning plugins were the same for all, but the setup of them was slightly different for each server type.

Keep in mind that VPS hosting is significantly different from any shared plan on any host and will also affect your caching plugin results.

Be sure to see the test results and notes for your type of host server.

Site conditions

To get real-world results from these tests that we could all trust and put to use, I simulated the type of site that I and most of my clients own. See the More about the tests brief below the results.

Basically, the site consisted of Genesis and child theme, all my fave plugins that I won’t do a site without, 3 big images in the post, 2 images in the sidebar, and 3 images in the footer, an optin in the sidebar and under the post, and 7 comments, both with and without generated gravatars.

(Thanks to all of my Webmasters for helping with the comments and suggestions for what should be included on the site!)

Cache plugin conditions

I used the most basic settings and as close to the defaults as I could, except on W3TC. I set it the way that I know it works best because the defaults on it are not as elaborate as the defaults on the other plugins.

In other words, I set W3TC closer to the defaults on the other plugins so I could test apples to apples.

With WP Fastest Cache, the main setting I changed was turning GZip on. And I would suggest you do too, if you use that plugin, especially on Apache servers where it has the most effect. (I actually tested with GZip on and off. Results here are with it on.)

I stuck to only page and browser caching with all of the plugins.

I also turned on Preload on all plugins that had that option available.

And the winners are…

Okay, I won’t keep you in suspense any longer.

The 3 top caching plugins are:

• WP Fastest Cache – free, with premium option
• WP Rocket – paid only
• W3TC – free, with premium option This plugin is too unstable for me to recommend anymore

I tested the free versions of all plugins where available.

LiteSpeed Winner

• WP Fastest Cache was the best on a LiteSpeed server.
• WP Rocket was a close second.
• W3TC was not far behind.

In fact, all 3 of these plugins had pros and cons that averaged out to give nearly identical end results. However, every one of them also had at least one critical flaw that made them appear worse on some tests compared to no caching at all.

Apache Winner

• W3TC was the best on Apache.
• WP Fastest Cache and WP Rocket were tied, and not far behind W3TC overall.
• * With WP Fastest Cache, you must turn on GZip to get the highest performance. On LiteSpeed, it made a marginal difference. On Apache it made a huge difference.

Apache with nginx Winner

11/7/16 I’m still running tests on this server configuration. Here’s what I have so far.

• WP Fastest Cache provided no improvement over WP Super Cache

All 3 plugins had greater flaws on Apache than on LiteSpeed that made them seem worse on some tests than no caching at all. But then, with Apache, they also had a lot more ground to make up because it’s a slower server type and has no server side caching.

Overall, all plugins did improve site performance.

Other plugins tested

• WP Super Cache
• Comet Cache

Neither of these performed very well and I don’t recommend using them.

Plugins I passed on

• Hyper Cache
• Cachify

Both of these required end users to manually add files to either .htaccess or wp-config.

I don’t recommend that non-geeks do that. And since this post is mainly for DIY site owners, I left them out.

I’ll likely run separate tests on these in the future for my Webmasters because I’m curious to know how they will work. One of them had extensive documentation right in the plugin settings and is a crash course on caching all by itself.

The myth of easy to set up

WP Super Cache is a popular plugin for one reason.

It has a reputation for being easy to set up.

That myth is so prevalent that I see many of my site audit clients install it, but never touch the settings. That includes turning it on!!!!

(I see the same thing with Yoast SEO plugin – installed, but not configured, and it too is hurting their site.)

Even with it on, WP Super Cache fared poorly in my tests.

Having a plugin that is easy to set up but doesn’t work is like having a jar that’s easy to open but is empty.

Both WP Fastest Cache and WP Rocket are easy to set up too, and they work. In fact, they both have less configuration options than WP Super Cache. So, if you want easy and effective, change plugins.

FYI, when you delete a caching plugin, it leaves orphaned folders and files that need to be deleted before installing the new plugin.

Need help? 

Contact me to change over to a better caching plugin. It’s cheap and easy.

Get a better host

As I mentioned at the top of the post, your hosting environment has everything to do with your site performance.

Even with no caching plugin, LiteSpeed servers are faster and have server-side caching built in.

You have to make up a LOT of ground on an Apache server just to equal what LiteSpeed gives you by default.

I’m on an A2 Hosting (aff link) reseller plan where every cPanel offers what they call Turbo. (Reseller plans are super for designers to set up client sandboxes! They’re not just for reselling.)

You can get Turbo on just a single shared hosting plan too. Look for the one labeled Turbo. (Lite and Swift are both Apache.)

More about the tests

Following is a brief of my testing conditions.

And I want to say one thing about all test posts.

If you read a plugin recommendation post that doesn’t divulge their testing conditions, move along. I’ve read every caching plugin recommendation and testing post that has been published in the last 2 years and some of them are not even worth the digital paper they were written on. The testing conditions were poor, at best. At worst, they never even mentioned what type of host server they were on, or the plugin settings.

Without that critical info, you have no way to replicate their results with certainty.

Hosting environment for LiteSpeed

• A2 shared Turbo
• Turbo is not on
• SSD – (Solid State Drive)
• Litespeed has memcached and opcode on by default (server-side caching)

Hosting environment for Apache

• A2 shared Swift (the Lite plan is just too little and I don’t recommend it)
• SSD

Online testers

• WebPage Test – running 3 concurrent tests from Lincoln Nebraska on Chrome, 2 views
• GTMetrix – average of 3 individual tests, from Dallas, Chrome, Unthrottled
• Pingdom – average of 3 individual tests, from Dallas
• WebSite Pulse – for header check

Testing method

• Set the URL in each tester
• Pinged the post in a couple of browsers to set it in memcache on LiteSpeed
• Started all tests simultaneously immediately afterward
• Cleared out the plugin/folders/files/directives between each test

Disclaimers

As mentioned, I’m already on an A2 reseller account, which I pay for annually.

I purchased the A2 Swift account for these tests.

I also purchased the WP Rocket plugin.

None of the vendors knew that I was running these tests and as such, were not asked and did not offer any special help or conditions.

What I’m using

I’m actually using all 3 of the top plugins now. I run a variety of sites, all with different traffic and hits. Since I purchased WP Rocket, I might as well get the good out of it for at least a year, so I’ll likely be putting it on the BlogAid main site. For most of the other low traffic sites I’ll be using WP Fastest Cache. And I’m going to keep W3TC on at least one site so that I can see how it is behaving, as many of my clients are running it too.

There is only one thing I didn’t like about WP Fastest Cache. You can’t clear the caching logs on the free version. Of course, I know how to do that another way, but most site owners don’t. (FYI, they are not held in the database, but in a file.)

More to come

Caching is a big topic. I’ll be covering it more in depth with regard to hosts and settings with my Webmaster Level 5 members.

I’ll also be running more tests with these plugins and hosting environment tweaked to the max just to see how far I can take each one of them for ultimate performance.

Look for more posts in this category on hosting and caching and CDNS, plus other ways to speed up your site.

I’m here to help

A site audit will show you all of the performance hits on your site and you’ll have a clear plan of action to improve it. Plus, and this is the best part, you’ll understand everything that is going on, all in non geek-speak so you can make good decisions for your site now, and in the future.

Hear my site audit clients, who have sites just like yours, tell you themselves.