Slow website? Cache it. Too many visitors? Cache it.
Using a proper page-caching setup can have one of the largest performance impacts for a site in terms of both scalability and speed.
Some hosts or plans (like our high performance hosting!) offer a server-side or even edge (think CDN) caching setup that is managed for you. For hosts that don’t offer such features though, using a caching plugin can still accelerate your site by 2-10x.
There are multiple caching plugins in the WordPress.org repository, so we tested 9 of the most popular ones to see which one was the best.
Here’s what we used:
- Swift Performance
- Cache Enabler
- WP Fastest Cache
- W3 Total Cache
- WP Super Cache
- Simple Cache
- Comet Cache
- Hyper Cache
No paid plugins here – we used to free version of Swift, and were unable to obtain a WP Rocket license so we couldn’t test it.
All tests followed our extensive methodology and ethics policy. A few specific notes:
- We used Pingdom and FastOrSlow for initial pagespeed tests and loader.io to test scalability.
- Each plugin was tested on the same site with only the caching plugin changing.
- Tests were conducted on our shared hosting plans.
- The only enabled setting for all plugins was page cache. Compression, optimization, DB cache, and other options were all set to off.
- When available, the .htaccess caching option was used.
We utilized two test sites. One was a default WordPress theme with zero plugins. Another was a bbPress and BuddyPress forum built with Origin page builder and lots of widgets and (useless) plugins — to simulate a bloated site.
Without further ado…here are the results for Site #1 using Pingdom from San Francisco:
(Results were averaged from two test runs — we’ve added a fully static HTML version of the page for comparison)
|Lower = Better||Load (ms)||TTFB (ms)|
Loader.io (50 Simultaneous Threads):
|Avg. Resp. (ms)||Req./s|
*We have reason to believe Breeze cache was not working properly and caching pages, despite multiple attempts to get it to cache. As such, the results for Breeze should not be taken into account.
Overall, we found cached load times and TTFB to be quite similiar for most the caching plugins, with WP Fastest and WP Super coming out first, closely followed by W3 Total.
Stress-testing is where we start to see some more differences. Overall, Swift Performance, WP Fastest, W3 Total, and WP Super are tied for first, with all of them have 17-18 ms response times and 2750-2800 requests per second.
I’d guess that this is because of the use of .htaccess for caching, instead of PHP.
Let’s see if it’s the same for Site 2 (FastOrSlow):
|Lower = Better||Load (s)||TTFB (ms)|
With Site 2, we see an even closer tie with 6 plugins achieving near-identical load times.
Conclusion…And a Winner?
We’ve decided not to nominate a winner given the extremely close results that we got. We’ve ordered them into categories by performance though.
|Swift Performance, WP Fastest Cache, W3 Total, WP Super Cache|
|Simple Cache, Cache Enabler, Hyper Cache|
We’re only ranking these plugins here based on raw page cache performance, but overall, we found that the most there is minimal, if any, the difference in caching speed between the top-recommended plugins. It comes down to preference and other features that some offer that can further boost your site or cache it even more.