The Why?

Let’s start off with why I performed these tests in the first place? There are plenty of tests that show how much WordPress Caching plugin’s help improve load times. The problem with these tests is they’re a one off – and are prone to error at best and manipulation at worst. What I was really interested in finding out was do caching plugins improve load times over a longer timeframe that truly simulate reality.

So to perform these tests, I’ve progressively setup Speed Studies on our 8 Live WordPress Sites over the last 9 weeks to find out which Caching plugin is truly the fastest.

The Speed Study Goal

My goal when I conduct Speed Studies is to find out which strategies are the best at improving site speed.

I’ll implement each strategy using the following approach:

  1. Setup the strategy on all 8 of our live test sites
  2. Then for the following 3 weeks, use hourly monitoring via GT Metrix to independently gather the load times. To eliminate the possibility of location bias, I change the test servers each week, starting in Dallas, then London and finishing off in Sydney.
  3. Next measure the impact of each strategy by comparing the average speed before and after.
  4. Ultimately decide whether the strategy works?

The Contenders

Let’s quickly run through the 3 WordPress Caching Plugins that were tested:

WP Super Cache

WP Super Cache is a free caching plugin, with over 1+ million active installs.

W3 Total Cache

W3 Total Cache is also a free caching plugin with over 1+ million active installs.

WP Rocket

WP Rocket is a premium caching plugin that costs $39/year for 1 site.

The Results – 25 Jun 2017

After 9 weeks of testing, let’s take a look at how our individual hosts performed with each Caching plugin:

Fastest WordPress Caching Plugins - Individual Host Performance

Major Observations

  • When we look into which caching plugins produced the fastest load times for each host, we find that:
    1. W3 Total Cache was fastest for 6 of our 8 hosts with an average load time of 1.66s
    2. WP Rocket was fastest for 2 of our 8 hosts and recorded a slightly slower average load time of 1.74s
    3. WP Super Cache was significantly off the pace with an average load time of 2.41s
  • Therefore the overall observation from where I sit is that if your looking for a Caching plugin to help speed up your site, I would recommend going for W3 Total Cache as it is not only the fastest, it is also free!!

So the Fastest WordPress Caching Plugin is…

Fastest WordPress Caching Plugin