Icon for WordPress Performance and Cacheing Optimization

WordPress slow? 7 Tips to Improve your Performance

The time to load your website – speed – is one of the 4 most important ranking factors for Google: besides of easy usability, attractive and comprehensive contents plus positive reputation fast loading times are super important to be found better in the search engine.

So the loading time is also important for your businesses’ success: Amazon, for example, leverages it’s revenue by 1% for each 100 milli seconds of loading time, the online shop reduces (source).

To speed up your WordPress site we sum up the 5 most important things to do:

  1. Choose the right WordPress theme
  2. Use as few WP plugins as possible
  3. Compress all images and use the correct formats
  4. Use the best caching plugin
  5. Limit the amount of revisions in WordPress
  6. Check the php version and other hosting features
  7. Optimize your theme functions

1. Open your eyes when choosing the WordPress theme

There are thousands of free and premium WordPress themes for different kinds of use. Sadly, there is no standard for them so the quality of code and the performance differs often very extremely. Especially premium plugins, which are already sold millions of times, are often so extensive, that they slow down your website and so become contra productive.

So, when you do research for a theme check first it’s performance with Googles’ PageSpeed Insights and another independent tool like the WebPagetest or Pingdom. If the PageSpeed score is over 80 and the loading time below 5 seconds, you might check the theme more in detail. Then, the chances to improve the speed with the following measures are high.

2. Reduce the amount of plugins

The more different plugins (extensions) your WordPress site needs, the slower, insecure and high-maintenance it becomes. Because weak spots of all websites can almost every time be found in the plugins. And every plugin needs additional database and file calls.

So care when researching themes and plugins on the functions, you really need. E.g. a tool, which connects your blogposts automatically with Facebook events is totally redundant, when you can do the connection easily by linking both items manually. It’s the same with the SEO plugin: I don’t want to advertise poorly our tool, but it combines all relevant settings for SEO. Yoast instead, needs extra plugins for structured data, shop optimization and analytics.

3. Optimize all images

Images are often also the biggest performance killer. If you set them up wrongly, you could worsen every good website.

First, please care about the correct dimensions of your images. Just display the correct resolution. WordPress has an integrated processor for changing images to lower dimensions. Use that and avoid inserting images in original resolution, if their not already performance optimized.

Know-Your-File-TypesThen select the correct image file format for your images. For that, I recommend you to care about the info graphic of whoishostingthis.com. To sum it up please care about these rules:

  • Photos and images with high amount of different colors should be saved as JPGs with reduced quality for the web.
  • Graphics should be saved as PNG or SVG files. SVGs are vector based files which often need less size and look better, but you need a short code snippet to activate SVG support for WordPress. There do also exist plugins to activate that, but as we already learn you should avoid them.
  • Animations should be saved as animated GIFs or animated SVGs. Last ones are also in our site in use, look much better and need 3 times less memory than exactly the same GIFs.

Then, you should compress all images. With out SEO plugin you can do that while uploading your JPGs to WordPress. It’s stronger than the integrated compression of WordPress (from version 4.5 on).

There’s also a bulk uploader, with which you can reduce the media images quality in WordPress in one action, but this only works on “good” web hosts, who offer you enough memory. Bad or often cheap ones don’t have enough memory. So, then you should compress all images of your media directory and the new ones on your own computer with optimization tools like ImageOptim.

Hint: You should only optimize your media directory, as long as your images don’t rank in Google. That’s because images are also stored as digital code and if that changes Google can’t safe the information, too. So just limit the bulk optimization on new websites and always optimize your images before or through uploading to your WordPress media directory.

4. Use the best caching plugin

To reduce the loading time you should also use the server and user browsers’ memory. To do so install multiple caching plugins and test each one separately under the same setup, to compare them and find the fastest solution for your site.

Exemplary Settings for WP Fastest Cache. Screenshot of the plugin.
Exemplary Settings for WP Fastest Cache. Screenshot of the plugin.

E.g. we noticed that all sites with visual editors can be optimized best with WP Fastest Cache and all tips of this post. The premium version of WP Fastest cache and other (free and premium) plugins like WP Rocket und W3 Total Cache don’t make them as fast as the fastest one ;-).

Furthermore, you should think about (changing to another host and) activating Nginx on our web space. This small features boosts many websites additionally 1 second.

5. Limit revisions in WordPress

Most of us like the revisions of WordPress to detect content changes. But those revisions can slow down your website, when you don’t limit them. We recommend you to do so an limit the revisions on 3 to 10, depending on who often and small your corrections are. The better you are when texting, the lower the limit may be. This works easily by copy and pasting on line of code to WordPress.

6. Check PHP Version of your server

An outdated version of the programming language PHP can also slower down your WordPress site. We measured in different tests, that you can safe 10-20% of loading time by switching from PHP 5.4 to PHP 7.0, for example. To change that you have to check your web hosts settings. If you don’t find anything there, you must ask the support, which version is active and if they can leverage the version for you. Please check then the compatibility of your whole website. If anything doesn’t work, you have to update the plugin/ theme,or lower the PHP version.

We also recommend you to check if your host supports SSD hosting with a Nginx-cache. This are two features which can also boost your site incredibly. If you have Nginx compatibility you should think about a Nginx controller plugin like this one to manage settings and flush caches when needed (we combined it in our site with the WP Fastest Cache plugin).

7. Optimize your theme functions

This point is a brief summary of the WordPress Performance Optimization guide of Sugarrae. It took us less than a minute to lower the page loading time for 0.5 sec. to 2.1 seconds:

WordPress Performance

With the following code snippet you can improve your WordPress sites’ performance by:

  1. Optimizing static resources
    Avoid duplicate requests for functions from static sites.
  2. Remove smileys / Emojis
    For all who also don’t like or need emojis they only mean redundant loading time.
  3. Remove WordPress’ embedding function
    This only makes sense, if you don’t embed tweets, YouTube videos etc. the lazy way by pasting their links. As long as you use the classical way of embedding by pasting the whole embedding codes, everything still works.

Here is the code to paste in the functions.php file of your WordPress theme:

/** Performance Optimization **/
//* 1. Remove query strings from static resources
function _remove_script_version( $src ){
$parts = explode( '?ver', $src );
return $parts[0];
add_filter( 'script_loader_src', '_remove_script_version', 15, 1 );
add_filter( 'style_loader_src', '_remove_script_version', 15, 1 );
//* 2. Remove WP emoji code
remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
remove_action( 'wp_print_styles', 'print_emoji_styles' );
// 3. Remove WP embed script
function speed_stop_loading_wp_embed() {
if (!is_admin()) {
add_action('init', 'speed_stop_loading_wp_embed');


If you already care in the concept of your website about performance when researching themes and plugins, you do everything correctly. Then care during the realization and communication on WordPress about your images and a fast cache. Furthermore, you should limit the revisions of your WP’s contents. All of this isn’t complicating and accelerates your website much.

But never forget to test your site intensively after each optimization:

  • Manually, by visiting your site with different browsers;
  • With tools like Google’s PageSpeed Test, Webpagetest and Pingdom at different times per day, to get a more objective impression.