Comparison of the 8 popular free caching plugins for WordPress: which one performs best?

Finding the best cache plugin isn't easy. You have to test it, measure its performance, find out about its long-term support...

So what's the fastest cache? What's the best cache plugin? Which are practical and complete, which are efficient? Do I need to pay for a good cache plugin?

Today, we're trying to answer these questions with independent measurements that are as objective as possible. The test is a bit "meta" in that it involves testing on lrob.fra showcase/blog created with FSE (full site editing). A standard, lightweight site.

Introduction

The objective of a cache plugin: to fall below 200ms response time or "TTFB" (Time To First Byte; 200ms is the maximum time recommended by Google PageSpeed Insights).

But not all caches are created equal, as Yoan De Macedo reminds us in his blog post. Some perform better than others, while others may even degrade performance. So to really choose the best cache, you need to test several on your own site and measure the results precisely. Given the variability of response times, it's important to carry out tests over a period of time and average the results. This can be tedious, however, so you may want to use this comparison test as a starting point.

We also remind you that caching isn't everything. Caching can reduce server resources, but your site must be optimized from the outset. Otherwise, it's called "cache misery". So opt for lightweight, well-optimized plugins and themes to avoid unpleasant surprises. The cache will then be the icing on the cake.

Plugins tested

I have based this list of plugins to test on a "top" list of caching plugins as well as on my experience with plugins actually encountered by various hosted customers:

1. Autoptimize
2. Breeze
3. Cachify
4. LiteSpeed Cache
5. WP Fastest Cache
6. WP-Optimize
7. W3 Total Cache
8. Bonus : Solid Performance (new plugin)

Test protocol

This LRob test is in no way sponsored by any caching plugin. It is intended to be as objective as possible. However, this test is only a reflection of itself and of our opinion, which cannot be perfectly objective and is therefore not intended to produce general truths. LRob is a independent web host specializing in WordPress.

Website details

The test is performed on https://www.lrob.fr/. The WP-Cron function is deactivated and executed directly by the server every 4 minutes. The site runs under PHP 8.3.12 in dedicated FPM behind Apache 2, with MariaDB 11.4. Redis server is also available on the host server (version 5:6.0.16).

Theme

The site is built with FSE and the Twenty Twenty-Four theme.

Plugins

The site has 17 active plugins at the time of testing (not including the cache plugin tested):

See the list of plugins

• How to use Blacklist Updater
• Complianz | GDPR/CCPA Cookie Consent
• Connect Matomo
• Easy WP SMTP
• hCaptcha for WP
• Insert PHP Code Snippet
• Optimize Database after Deleting Revisions
• Rank Math SEO
• Regenerate Thumbnails
• Simple Local Avatars
• Site Reviews
• Social Sharing Block
• TranslatePress - Developer
• TranslatePress - Multilingual
• Update URLs
• WPForms Lite
• WPMasterToolKit

Measurements and details

Response time is measured with Uptime Kuma on a server at PulseHeberg in Switzerland (Lausanne), which provides this average. The production server is located at Hetzner in Falkenstein, Germany.

Each plugin is tested successively, with a measurement every 20 seconds for 5 minutes or more (sometimes I went for a coffee in between), i.e. a minimum of 15 measurements to obtain a consistent average.

Between each test, Uptime Kuma's recorded values are erased after an initial measurement once the cache is in place; the cache folder is deleted and it has been verified that the .htaccess and wp-config.php are indeed free of any trace of the previous plugin.

Protocol limitations

The test was carried out on a server in production, generating a slightly higher variability of results than that observed on a server with no activity. However, server usage is very moderate at the time of the test, and the variability is offset by a series of over 15 measurements each time, enabling the results to be averaged. The aim is not to get the value to the nearest millisecond, but to obtain an order of magnitude.

Furthermore, the test was carried out on a specific site and cannot be extrapolated to all sites: every site is different and will respond differently to certain plugins (particularly stores). But if your site is made with the Twenty Twenty-Four theme or another FSE (Full Site Editing) theme, then chances are your results will be similar.

Tests and Benchmarks

Baseline - Test control: Response without cache plugin

Without any caching plugins, the site responds in 379ms on average, with little variability. This is a relatively low base value, since sites made with builders can easily take 2 to 4x this response time.

Let's take a look at how different caching plugins improve response times.

Autoptimize

Average response: 379ms

The response time is identical to the site without cache. And for good reason: Autoptimize's caching function is in fact only available with the paid plugin. In other words, you won't be able to speed up your site with the free version. That's a shame.

However, as the developer points out Simon JANVIERAutoptimize, in its free version, is more useful for intelligent concatenation and minification of scripts. In this respect, it can lighten your site, but will not improve its TTFB (response time).

Breeze

Contrary to what I initially thought, Breeze isn't just for Cloudways or Varnish, it also works on a classic system. I therefore add it to this test and thank Michael GOUT for bringing this plugin to my attention.

Average response: 98ms

The result is amazing: under 100ms with very stable response times! I'm just discovering this plugin and I'm falling out of my chair!

I have a minor reservation about the plugin's compatibility with all sites, due to the comments on wordpress.org. From these comments, it seems that its use could cause some problems with the most dynamic or complex sites, such as WooCommerce e-commerce sites.

For the rest, it seems an excellent choice not to be missed.

Cachify

Cachify offers database caching by default, and also supports file and Redis caching. We tested the default cache and Redis. Apart from that, very few other settings are available to us.

Average response: 260ms

The results are similar between the "Database" cache and Redis, within the margin of error. However, the results seem to be more stable with Redis. In all cases, the result exceeds the expected 200ms, which is disappointing. This plugin cannot really be recommended.

LiteSpeed Cache

LiteSpeed Cache has been in the news a lot recently for its security flaws. The plugin also claims to correspond to an Apache server. So how does it fare in practice?

Average response: 376ms

A disappointing result for LiteSpeed cache on our test configuration, since the site is within the margin of error of the site's original response time, without cache.

And for good reason, as Louis ChanceLiteSpeed, as its name suggests, doesn't cache anything on an Apache server! You need an available LiteSpeed server. We can't recommend this plugin if you're running Apache, given the performance it delivers and the many recent security flaws.

W3 Total Cache

W3 Total Cache offers a configuration wizard and numerous settings. It's the most complete free plugin I know. It supports various cache types, including Redis. Here, minification has been activated, which may slightly increase the measured response time but offers better performance for visitors with slower connections (mobile, ADSL, etc.).

Average response: 159ms

Finally, a result under 200ms! With Redis, so avoiding thousands of cache files. And great control over settings and options like Lazy Load for images, and disabling certain optional WordPress scripts. Its versatile configuration will enable you to adapt more precisely to each site: you can measure the performance obtained with different settings and choose the most relevant for your specific site.

In addition, the other types of cache available also perform well, although not tested today, the results are fairly similar whatever the type of cache chosen.

In our experience, this plugin has never disappointed, so it's highly recommendable. (It's even LRob.fr)

WP Fastest Cache

This plugin offers some interesting options in its free version. However, some of the options offered free with W3 Total Cache are missing.

But the most important thing today: does this plugin live up to its name, by actually being the fastest?

Average response: 123ms

This plugin lives up to its name, being one of the fastest tested! In our test, however, Breeze came out on top.

At LRob, we've seen many diverse blogs achieve great results with this plugin. It has never disappointed, and we recommend it without hesitation.

WP-Optimize

WP-Optimize offers very few cache settings. In fact, its primary function seems to be database cleansing. So how does it fare when it comes to caching?

Response time variability is too high for our liking, with responses oscillating between 132 and 180ms.

Nevertheless, the average remains very good at 152ms. A pleasant surprise.

We're not at all reassured by this variability, and so don't recommend this plugin as a cache. All the more so as we've already observed sites that were slower with this plugin than without... So use it with caution as a cache.

Solid Performance

As a bonus, I'd like you to try out a new caching plugin, Solid Performance, which looks promising. (thanks to Julien ROUSSEL for recommendation).

Average response: 155ms

Although it provides no adjustment whatsoever, its measured response time is among the best in this test. Enough to potentially satisfy those who don't feel like making the slightest adjustment. As the plugin is young, it hasn't yet been tested, but a cache plugin can easily be changed if necessary in most cases, so there's not much risk in trying it out if you feel like it!

Summary of results and conclusion

Plugin	Average response (ms)	Percentage (lower is better)
Baseline (no cache)	379	100%
Autoptimize	379	100%
Breeze 🥇	98	25.8%
Cachify Database	257	67.8%
Cachify Redis	263	69.4%
LiteSpeed	376	99.2%
W3 Total Cache Redis 🥉	159	41.9%
WP Fastest Cache 🥈	123	32.4%
WP-Optimize	152	40.1%
Solid Performance	155	40.9%

We have no hesitation in recommending Breeze, WP Fastest Cache and W3 Total Cache which are all excellent. They offer very good response times with sufficient settings, even in the free version. It should be noted, however, that Breeze may cause a few problems on some sites. Also, W3 is a little more complete in the free version than WP Fastest Cache, which is why it has been chosen for WP Fastest Cache. LRob.frbut Breeze could potentially replace it in the long term, as it provides almost as many functions while being simpler to use.

In summary, according to our test :

• Choose Breeze for maximum performance, rather for showcase sites
• Choose W3 Total Cache for the highest level of customization, or if your host supports Redis (as is the case with LRob accommodation)
• Choose WP Fastest Cache for excellent performance without configuration

A mention for WP-Optimize, which despite its lack of settings and wide variability in response time, shows a perfectly decent average response time. Mention also to Solid Performance which, as a newcomer, lives up to its name and looks promising without revolutionizing anything, as it stands, due to its lack of settings. Cachify's settings and performance are inferior to those of other plugins. We can't comment on LiteSpeed in our Apache configuration (except to say that its usefulness is very limited in this type of configuration). Autoptimize, finally, offers no improvement in loading times and is therefore totally useless for this purpose, according to our measurements, but could be used in conjunction with a caching plugin to reduce the number of files.

Given the good results obtained with these free plugins, it doesn't seem essential to pay for a cache plugin if you don't need the additional functions offered. We may, however, test the paid versions in a future article, if you're interested.

It goes without saying that high-performance hosting is essential to achieve the best response times. To achieve this LRob accommodation are here to serve you (in every sense of the word)!