WordPress website slow? These are the reasons

Maik Gruppen, September 26, 2018

Does your WordPress website take too long to load? Or are there specific pages that have this problem? In both cases, it would be wise to find out the cause of this problem. A slow website is not good for number of visitors and conversion numbers.

In this article, we show possible reasons for a slow website. Subsequently, we explain how to find out the exact reason for your speed problems.

Reasons for a slow WordPress website

Various reasons can cause your WordPress website to be slow. We have listed the most common reasons for you.

Many complex requests

Especially with a busy and heavy-duty website, large numbers of complex requests can pile up to a bottleneck, which slows down loading of a page. For example, think of a web store in which a customer orders and pays for multiple products at the same time. The customer’s computer then sends a request to receive the check out page.

At that moment, the server not only has to collect the layout of that page, but all information about the products as well and generate a corresponding shipment. A peak of such requests can result in loss of speed, especially if caching techniques are not used optimally or your hosting falls short.

Bad hosting

When choosing a hosting party, it is very tempting to look mainly at price. However, you often get what you pay for. Especially when choosing a cheap shared hosting package, there is a risk (too) many websites are placed on one server. If you own a complex website with many visitors, this will quickly lead to a decrease in speed and performance.

In such a case, it is better to choose a VPS server. Hosting techniques like a fast server, caching, possibilities for CDN integration or the latest PHP/MYSQL versions, offered by Savvii, will speed up your WordPress website.

Themes for WordPress

Flexibility is one of the strengths of WordPress. This feature is displayed, among others, in the large available number of themes for the platform.

Unfortunately, there are also bad themes that can slow down your website significantly. This is due to the fact that they often use poor coding, produce too much code or invoke too many extra files unnecessarily. Better delve into a theme before you decide to use it permanently or consider choosing a new theme.

An abundance of plugins

Installing plugins is an easy way of providing your WordPress website with a range of extra features. However, abundance harms.

An excess of plugins often decreases the speed of your website, especially when some run on badly written codes. Always check whether you really need a plugin or if it is a funny gimmick which is not essential for the functioning of your website. Plugins in the latter category should be removed.

Oversized images

Oversized images are a main reason for slow WordPress websites. An overview of common mistakes when using images in WordPress.

  • Images are not downsized with regards to number of pixels or optimized before placing them in the media library. The result: a lot of MBs and long loading times. Use tools like WP Smush to downsize your images
  • Website owners use the wrong file format. JPEG or PNG is the most suitable format for online use, by far. A file format like TIFF is much more focused on printed products and does not use compression. This results in much larger image files.
  • A CDN is not being used. Especially when you have visitors from over the world, a CDN ensures faster issuance of your images.

Bad configuration

The technical configuration of WordPress on the web server itself can be a source of speed problems as well. Therefore, choose settings and techniques aimed at optimization of loading times. Examples are minifying files, lazy loading images and videos and caching (e.g. with WP-Rocket) of individual pages.

Unraveling the cause of a slow website

But how do you find out what causes your WordPress website to lack speed (the principle is that a website or page should load within a second)? Luckily, there are several tools available to find out why your website does not load quickly.


This tool uses multiple sources when measuring the speed of your WordPress website. How does it work? First, you enter the URL of the desired web page. Subsequently, you receive ratings of F to A and from 0 to 100 percent. A minimum score of 90% is an excellent value. Extra useful is the fact that GTmetrix provides specific suggestions to improve the speed of a website or page substantially.


With Webpagetest sites are being loaded a number of times, after which a report is published using waterfall charts. With this you quickly can see which assests of your site or loaded slowly and you have to focus on fixing. The report also shows some essential loading time metrics: speed, Time to First Byte, Time to Render and website size.


Pingdom provides valuable information about the total loading time of a website. Those insights are linked to an overall rating which is indicative for the general performance of your website. Pingdom’s verdict is also translated to specific suggestions which can boost loading times. What are the strengths of my website? And which actions can I take to refine performance? Pingdom is pretty technical, so mainly useful for hosting companies and developers.

Google Analytics

Using Google Analytics will provide more insight on the problematic pages within your website and makes it easier to improve poorly performing parts of the website.

Google PageSpeed Insights

PageSpeed Insights by Google provides, just like GTmetrix, a score per page. The advantage of this tool is you immediately receive a rating for the functioning of your web page on a smartphone. Pretty important in an era in which people increasingly enter the digital highway using mobile devices.


As you have seen, there could be many causes for a slow WordPress website. To get the best out of your website, it is important to trace the slowing elements as soon as possible. Luckily, plenty of tools are available to help you achieve this.

Want to learn more about measures you can take to improve the speed and performance of your website? Please contact one our specialists.

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