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WordPress Site Speed – Using to test your site

Karl – a web developer with Wibble web design Belfast
By Karl Proctor 19 August, 20195 MIN READ
WordPress Site Speed - Using to test your site

WordPress sites are really slow!” – this is something that we hear quite a lot, both from prospective clients and also from developers / web companies who don’t specialise in all things WordPress or want to entice clients away from this open-source option.

In this post, our senior developer, Karl, looks into site speed with WordPress and how a custom theme is probably a better option than a pre-built theme.

Two very important aspects of a good website are the site speed and accessibility. A site should be fast and performant, loading in the shortest amount of time that your WordPress site or server will allow. This would be regardless of the device and connection speed. It would need to be accessible, making the site reachable for as many people as possible.

Testing a WordPress site for speed homepage testing for performance, accessibility, best practises and SEO resource for testing sites against: performance, accessibility, best practises and SEO

You can test your site for these aspects using many tools. One of the best we’ve found is called, which is a relatively new tool created by Google to test a website. It tests for speed and accessibility, as well as best practices and SEO, two other very important aspects for a website.

The tool is useful for testing and giving scores for the 4 key areas it tests, giving a breakdown report of what is going right and what’s going wrong. As well as highlighting the problems, it will also give options and hints on how to fix things. speeds for
Example of speeds

For the WordPress sites that we design and build, we use tools like throughout the build process to make sure that the site is meeting the requirements that the tool sets out.

Why some WordPress sites are slow

One of the biggest areas that the tool points out are in regards to site speed, and it has to do with image and file requests. When you visit a webpage, you’re commonly downloading a number of styles, scripts and images. If you’re using a pre-built theme, you’ll find that these tend to include many more files and the tool will highlight this. This “code bloat” is due to a theme providing many features, such as sliders, testimonials, audio players etc and this code is loaded even if your site doesn’t use them – these are all downloaded every time your site is viewed.

One of the benefits of getting a custom theme made for your site is that Wibble have complete control over what files are downloaded, keeping this a minimal as possible. The less the user has to download, the faster the site can be for them to use. For E-Commerce sites, this can result in more users and more sales – site speed in regards to e-commerce development can be critical.

The tool is very good for bringing issues to light that could be easily missed. One such thing is the JQuery version that ships with WordPress. By default, they provide 1.12.4, which has two security vulnerabilities. The most recent version of JQuery is 3.4.1, and the current version that ships with WP is over three years old. The vulnerabilities aren’t very big issues, but they’re things that could be fixed. The reason WordPress still provides them is likely due to backwards compatibility reasons with other browsers and older versions of plugins etc. Something like this is hard to detect, especially when you wouldn’t expect a default file to come with a security issue.

Carousels and site speed implications

Oh and don’t use carousels, they’re bad. They require multiple files, including CSS and JS, and the stats from Google says under 1% of users actually use them. The benefit of a slider is almost non-existent. Instead, focus on laying out your content on the page in an accessible way, and you’ll find there is higher interaction and fewer files to download.

1% of users interact with Sliders


Google’s own UX playbook states the disadvantages of using carousels and this is one of the reasons we are no longer implimenting them in new builds.

Based on all of the above, we try not to use sliders because of the lack of interaction from users and the site speed implications to download and display the slider. For instance, on the homepage of the site, we load a random project on each load instead of displaying a slider there. It’s quicker to load, and it still shows off different projects on different page loads. It also gives the site a nice dynamic aspect.

ISGE Featured Project on Wibble Homepage
ISGE on Homepage
Irish Echo Featured Project on Wibble Homepage
Irish Echo on Homepage

Plugins and effects on site speed

Using poorly optoised plugins but especaially poor plugins for sliders, such as RevSlider, can add a lot to the page load times, as it’s not very optimised compared to a custom slider or a solution like the one above for the home page of Non-optimised sliders tend to require many files and people tend to add many slides to the slider. If these images are all downloaded on page load, this can dramatically slow down the page.


Essentially, less files will likely result in faster speeds. When it comes to a pre-built theme, they don’t tend to accommodate this. That’s why when we build a theme, we try to keep the files requested to a minimum.

Is WordPress slow? Yes and no!

Yes, it is when you don’t develop it properly.

No, it isn’t when the site is built with care and consideration.

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Karl – a web developer with Wibble web design Belfast

Karl Proctor

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