• 10 hours
  • Medium

Free online content available in this course.



Got it!

Last updated on 9/2/20

Improve the Speed of a Website Built With a CMS

According to W3Tech,  33% of the world’s websites built in 2019 used Wordpress. You will probably have to work on a website created with Wordpress or a similar CMS sooner or later.

Here's how to improve their performance!

Pick a Fast Theme (and Builder)

Most CMS allow you to install a theme (a template designed to make your work easier) and/or a theme builder, which allows you to create your pages by dragging and dropping pre-built elements.

Here are some things you need to know when picking a theme and builder:

  • The theme must be fast. It shouldn’t have too many CSS animations or JavaScript to block content from being displayed. You can find this information in the theme description. Additionally, most themes offer an online demo version, whose speed you can test on Pingdom or GTmetrix.

  • The theme must follow good SEO practices. For example, no multiple H1's on a page.

  • The theme builder should not significantly slow loading time for your pages. Try a page on your site with and one without, and compare the results.

The issue with many builders is they add a lot of extraneous HTML code to pages.


  • Elementor is a free, lightweight theme builder.

  • Another excellent choice is Beaver, but it isn’t free.

These two theme builders offer built-in themes.

Capture d'écran - GeneratePress

Eliminate Unnecessary Plugins and Resources

Every CMS provides optional plugins/modules/extensions.

These plugins allow you to add certain features without having to code them, such as reservation or payment modules.

If you have installed plugins that you no longer use or that are unnecessary, you should disable and delete them. You can quickly identify which ones slow down your website by manually disabling them in turn and then measuring server performance. By removing unnecessary plugins, you can dramatically improve page load time.

Be aware that the total number of plugins is not necessarily a determining factor. You can have fifty plugins and still have a fast website. The quality is more important.

For example, plugins for sharing on social media can significantly affect your page’s loading time. Therefore, you should consider either developing yourself or having a developer integrate social media sharing directly in the source code of your website’s theme. Avoid these kinds of plugins and, more broadly, those which load lots of scripts.

Ask Yourself the Following Questions Before Installing a Plugin

  • Is this a high-quality plugin (good reviews, updated frequently by developers)?

  • Is the plugin compatible with your CMS?

  • Is the plugin essential?

Take the time to make sure you are going to use all the features of the plugin and not just some minor ones. And, importantly, check that you can’t code it yourself!

Optimize Your Images

As explained in Chapter 2, images often weigh down a page. Every CMS has (free) plugins that automatically optimize the images you upload to your site.

There are several great plugins for optimizing images in Wordpress:

For other CMS, Google "image optimization plugin + [name of CMS].”

Install a Cache Plugin

Cache plugins usually allow you to do more than simply set up caching. They also allow you to minify and compress resources.

You can also choose your plugin based on your theme. Professional theme creators often optimize their themes for a given cache plugin to boost performance.

Let's Recap!

  • Choose a quality theme.

  • Uninstall unnecessary plugins.

  • Install a good site acceleration plugin.

  • Don’t forget what you learned in Chapter 2. It also applies to CMS!

You have now completed the first two parts of the course! Don't forget to do the quiz and activity to help you review what you’ve learned. In the next part, we'll look at how to optimize a website built with a JavaScript framework.


Ever considered an OpenClassrooms diploma?
  • Up to 100% of your training program funded
  • Flexible start date
  • Career-focused projects
  • Individual mentoring
Find the training program and funding option that suits you best
Example of certificate of achievement
Example of certificate of achievement