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:
- Setup the strategy on all 8 of our live test sites
- 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.
- Next measure the impact of each strategy by comparing the average speed before and after.
- Ultimately decide whether the strategy works?
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 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:
- When we look into which caching plugins produced the fastest load times for each host, we find that:
- W3 Total Cache was fastest for 6 of our 8 hosts with an average load time of 1.66s
- WP Rocket was fastest for 2 of our 8 hosts and recorded a slightly slower average load time of 1.74s
- 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!!