We explain why your WordPress site is too slow despite fast hardware and special hosting and present the 5 most common causes for low WordPress speed.

We experience it almost daily: a customer writes to us in the support chat because his site just won't get any faster. Despite server optimization, appropriate plug-ins and sufficient computing power. Other customers, on the other hand, are happy abouttheir pages being as fast as an arrow. We asked ourselves, "How can this be?" and compiled the five factors that make WordPress particularly slow in our experience.

Let's keep it short. These are the five biggest WordPress speed killers:

1. Missing caching
2. Too many and not compressed images
3. Uncompressed and non-summarised code
4. Lack of above-the-fold optimization
5. Pages far too large

WordPress Speed Killer 1: Missing Caching

Caching is a fast and highly effective way to make your site faster. A cache can be understood as a kind of short-term memory: If, for example, the browser remembers what a web page looks like, it does not have to ask the server for the necessary data first, but the browser can load the site directly from the cache. This speeds up the page loading time for returning visitors immensely.

Now caching is not a simple topic. There are many different types of caches that can be installed and activated in many different places. To get an effective caching solution quickly, you should rely on widely used and proven caching plugins such as WP Super Cache, Cachify or W3 Total C ache. You should also ask your host which caches it has activated. You have a solid basis if at least a browser and server cache are activated.

A cache has the disadvantage that it is usually only used when the user has already visited site at least once. In many cases, however, it is important that the website builds up quickly and smoothly the first time. If you want to achieve this, you have to get to work on the page bacon.

WordPress Speed Killer 2: Images and graphics

Another killer for your WordPress speed are images and graphics. Optimising them is an art in itself, because you have to consider a lot of factors: The file format, scaling, compression and much more[1].

Mostly, however, very simple behaviours, such as a plethora of unnecessary images or an unsuitable file format, lead to long loading times. Here, too, plug-ins provide a remedy. These compress and optimise images during and after upload and significantly increase your WordPress speed. Examples of this are Optimus and WP Smush.

WordPress Speed Killer 3: Unordered and uncompressed code

Every website consists of code. It determines pretty much everything that makes up your site : layout, colouring, text and so on. It is therefore the construction manual of your site. But not all code is the same: You have to distinguish between CSS, JavaScript and HTML. These types of code are responsible for different areas of the website - CSS for images, for example, and JavaScript for animated content. Therefore, different types of code also show different loading behaviour. This can lead to certain commands blocking each other.

Such loading bottlenecks or blockades slow WordPress down considerably. Therefore, it is common practice to combine code into as few files as possible, compress them and put them in as good a loading order as possible.

You can hardly avoid a tangle of code without the appropriate knowledge of CSS, JavaScript or HTML. For this reason, there are plugins that help you to organise and summarise the code of your site . Examples include Autoptimize and Better WordPress Minify.

WordPress Speed Killer 4: Lack of Above-the-Fold optimization

All optimization is of little use if the user is not presented with a perceived faster site in the end. Because this perceived speed ultimately determines whether a site benefits from performance optimization.

In practice, a so-called above-the-fold optimization is therefore often carried out. Above-the-fold describes the area of a website that is visible without scrolling, i.e. the first impression that a user gets of a website. The aim of the optimization is to ensure that this area builds up as quickly and smoothly as possible. To achieve this, the loading order of the visible elements is adjusted accordingly. All elements that do not belong in this area are placed at the back, as they are not visible at first and are therefore not relevant for the first impression of the page.

Therefore, conceptual considerations are at the core of this type of optimization: You have to be clear about what content a user needs to be shown so that he or she completes the desired conversion. There is no quick and easy solution to this.

WordPress Speed Killer 5: Pages that are too fat

This brings us to our last performance killer: the size of the page. Many slow pages are simply too big, have too many plugins installed, an unnecessarily large theme, or are overloaded with images and graphics. This is good news! Because it means that WordPress performance can be increased very easily in many cases. If you regularly clean out your site , you can usually keep your page load time at a good level.

Conclusion: Summarise and compress, summarise and compress, summarise...

In principle, everything boils down to summarising and compressing content. This is the only way to get the most out of your WordPress. The places where this works particularly well are the images, the code and the overall concept of site. If you then also use caches and regularly muck out, you have created good conditions for optimal use of the available server power.

Thus, although host and the server determine the basic performance potential of your site, what you make of it is entirely up to you.

In the coming articles, we will address the question of how to identify bottlenecks in your WordPress performance and how to solve them.

Of course, there are other WordPress speed killers than those listed here. Can you think of a particularly important point? Feel free to leave a comment and help the community to optimise their pages even better.

Sources

[1]: Short introduction to the theory and practice of image optimization on WordPress by the colleagues from pressengers: http://pressengers.de/tipps/wordpress-grafiken-komprimieren/