In June of 2021 an SEO plugin for WordPress boasted they were “one of the fastest SEO plugins” available, so using the Query Monitor plugin, we tested the performance of several SEO plugins to see if their claim was true (spoiler alert, it wasn’t).
In the months since that article, there has been a new version of WordPress and new versions of several SEO plugins, so we were curious to see if the SEO plugin performance results had changed for Q4 2021. The WPSSO Core plugin, for example, has integrated their Schema JSON-LD add-on into their Core plugin, so the features of WPSSO Core have increased significantly – would it also affect its performance?
We’ve classified the performance of each SEO plugin into one of three categories (best, average, and worst), and included a new baseline chart for WordPress with the 2021 theme and just the Query Monitor plugin. This gives us a good reference for the performance impact of each SEO plugin – as you will see, the best performing SEO plugins have almost no effect, while the worst almost double the page load time and number of database queries!
In the following charts, a grey background is used to highlight results that are not significant, while green, yellow, and red are used to classify an SEO plugin as best, average, or worst – and the performance metrics significant to that classification. The number of database queries, for example, is very significant.
Baseline Performance Chart
| Version | Page Gen | DB Queries | DB Query Times | Peak Mem | |
|---|---|---|---|---|---|
| WordPress | 5.8.1 | 27 ms | 28 of 34 | 1.5 ms of 1.8 ms | 5,690 kB |
| 2021 Theme | 1.4 | 2 of 34 | 0.1 ms of 1.8 ms | ||
| Query Monitor | 3.7.1 | 4 of 34 | 0.2 ms of 1.8 ms |
SEO Plugin Performance Chart (Singular Post)
| SEO Plugin Name | Version | Page Gen | DB Queries | DB Query Times | Peak Mem |
|---|---|---|---|---|---|
| WPSSO Core | 9.0.1 | 30 ms | 2 of 36 | 0.1 ms of 1.8 ms | 6,664 kB |
| The SEO Framework | 4.1.5.1 | 30 ms | 4 of 34 | 0.2 ms of 1.8 ms | 6,694 kB |
| Squirrly SEO | 11.1.09 | 33 ms | 7 of 34 | 0.3 ms of 1.7 ms | 6,406 kB |
| WP Meta SEO | 4.4.3 | 30 ms | 8 of 40 | 0.4 ms of 2.0 ms | 6,524 kB |
| Yoast SEO | 17.2.1 | 35 ms | 8 of 37 | 0.5 ms of 2.0 ms | 7,913 kB |
| SEOPress | 5.1.0 | 43 ms | 10 of 37 | 0.5 ms of 1.8 ms | 6,367 kB |
| Rank Math SEO | 1.0.73 | 38 ms | 17 of 44 | 0.9 ms of 2.3 ms | 7,313 kB |
| BoldGrid Easy SEO | 1.6.10 | 40 ms | 4/2/3** of 40 | 3.3 ms of 7.2 ms | 6,010 kB |
| All in One SEO | 4.1.4.4 | 56 ms | 34/7/0** of 67 | 5.8 ms of 8.1 ms | 7,925 kB |
Data updated on 2021/10/01 using the Query Monitor plugin viewing the WP Test "About" page with a featured image selected.
** Denotes an SEO plugin that uses additional select/show/update database queries (instead of only selects).
About the Results
Some things to keep in mind when looking at this chart:
- The number of database queries in these results is very significant – most hosting providers offer very poor database performance, and dedicated / self-hosted VPS servers rarely have a properly tuned database. I would avoid any plugin that significantly increases the number of database queries.
- When activating a new plugin, it’s always a good idea to measure the performance before and after activating the plugin. If a new plugin negatively affects the performance of your site, you should definitely consider alternatives.
- Not all SEO plugins are equal in terms of features – all SEO plugins should offer the basic SEO meta tags (ie. description and canonical URL meta tags), but a few plugins, like the WPSSO Core plugin, also include extensive social meta tags and Schema JSON-LD markup for Google Rich Results.
