The 10 Most Important Levers to Improve WordPress Performance

Torben Simon Meier Updated on 21.10.2020
10 Min.
WordPress  Performance: The 10 most important levers
Last updated on 21.10.2020

The web is teeming with tips and tricks on how to optimize your WordPress performance. Unfortunately, the explanation and relevance of the various optimization measures are often ignored. We show you the important starting points and tools – in a sensible order and with context. This way you will see improvements very quickly.

So far, we have already hosted about 15,000 WordPress projects. A whole lot of data has accumulated in the process. And we are constantly being asked by customers how they can further reduce the page load time of their WordPress projects. So we have systematically processed our findings from the analysis of our customer sites from previous years. The result: 10 measures with which you can quickly and easily optimize your WordPress performance.

One thing is especially important: Some users are quickly taken by the optimization suggestions of tools such as Google PageSpeed Insights . Let me tell you: Most improvements of your loading time you don't need complicated optimization measures for. Much rather it takes a few measures that are pretty easy to implement.

WordPress performance optimization suggestions by Google
Only few site operators can do something concrete with this message. Therefore, it is especially important that you concentrate on the simple optimization steps first and tackle the more complicated measures later on.

Of course loading time optimization is not an end in itself. Besides a better experience for your users, a shorter loading time also brings benefits your visibility on Google and the like.I will therefore briefly outline what the individual optimization steps are actually about in order to create the appropriate context.

So you can theoretically work your way through from top to bottom and thus improve the loading time of your site step by step. By the way, the first seven points also refer to the typical improvement suggestions of Google PageSpeed Insightsto which we refer, for example, in this article in more detail.

#1 Caching: The most important performance factor of all

Caching means that your site does not have to be requested from the web server by the browser first and then built up step by step. Instead, yours site is loaded (completely rendered) from a temporary storage.

The advantage of caching is obvious: WordPress does not have to newly build up your site every time you open a page. Because WordPress is based on PHP (which is quite slow), a cache is elementary here.

In principle, there are two implementation variants for caches:

  • About caching plugins: The majority of users use a caching plugin, like W3 Total Cache , WP Super Cache. These are sometimes simpler, sometimes more complicated to set up. In any case, a certain amount of manual work is required here.
  • About the web host: Some hosts like RAIDBOXES offer server-side caching. This means that you can almost always do without caching plugins. Because your hosting provider has the configuration of the cache already covered for you.

If you have set up high-performance caching, you have already taken the most important step towards better WordPress performance. For more details please have a look at our article on caching basics .

#2 Tidying up WordPress

One of the most common causes for long loading times is – in our experience – an overloaded WordPress installation. And because this point of improvement is not mentioned by Google PageSpeed Insights, it comes directly second in my top 10.

An overloaded WordPress installation means in most cases: there are too many plugins installed. In principle, the less plugins the faster the site. Of course, plugins are important and you can't do without them completely, but you should always check from time to time, which plugins you really need.

And: You should take care plugins not to simply deactivate them, but actually delete them completely.

Improve WordPress performance: Your plugin overview shows you exactly how many plugins you have installed, activated and still have to update.
Your plugin overview shows you exactly how many are plugins currently disabled. In principle, "Inactive" should always have a zero. If not, ask yourself exactly: Do I need the deactivated plugin ever?

The same applies to themes: You do not need more than one.

The background is this: Any plugin and theme adds PHP code to your site. This also applies to disabled plugins. This makes your site overall bulkier and thus slower (and more vulnerable to attacks). As I said earlier: PHP is a very slow scripting language. The less of it there is, the better.

Frequently, no longer needed plugins and themes are leftovers of function and design tests. Therefore, it makes sense to clean up your WordPress regularly. Also, you should always try new features and designs in a test environment not on your live site! That way you won't pile up too many leftover plugins in the first place.

#3 Images: The underestimated load time brake

One of the most effective and simple measures to reduce page loading time is the resizing of images. Because here you can partly save large amounts of data. The so-called "lossless image compression" will reduce the file size of your images without visible loss of quality. So your site hardly changes at all, but at the same time, you can reduce its size significantly with the help of image optimization.

Estimates of the site HTTP archive According to the study, images regularly make up the largest share of the data volume of a website. Minimizing your images should, therefore, be one of the first steps in optimization. You can either do an image optimization manually, or you can use a compression plugin.

Using plugins is certainly the more convenient solution. Not only do plugins allow you to compress new pictures and their thumbnails, they also automatically optimize all existing pictures from your site. However, this service is often subject to a fee.

#4 CSS and JavaScript: Sounds complex, but is easy to optimize

The second largest amount of your site data is usually JavaScript and CSS files. Many users show fear of contact here. But even without code expertise, you can easily understand what CSS and JavaScript optimization is all about. Because generally there are three things to do first:

  • Summarize: CSS and JavaScript are hidden in many small single files. Normally each of these files must be requested individually by the browser from the web server. This creates HTTP requests that site tend to increase the loading time of yours. However, when scripts are combined, the number of files to be loaded is reduced, and with it the number of requests. For example, 53 individual requests become only a dozen or so. Of course, the corresponding plugins can do that for you.
  • Minification: CSS and JavaScript files are lines of code that enable certain functions and designs on your website. This code is written by humans. But it is read by machines. Why is this relevant? Much of what a human being needs to understand code correctly is not needed by a computer. Spaces, comments, etc. are not needed to build your site correctly. Right here plugins like Autoptimize come into play. They convert CSS and JavaScript from human to machine readable code. This makes the individual data packets smaller and their transmission faster.
  • Compressing: After merging and reducing, the last step is to compress the data packets that are sent from the web server to the browser. This means that the server minimizes the file size of the individual requests and the browser unpacks and calculates them. This is faster than sending uncompressed data packets. You can set up a GZIP compression for example via caching plugins, via manual settings in the .htaccess or your host has already activated compression on the server.

Even without knowledge of the scripts, it is therefore easy to understand what the individual measures achieve. And for all three work steps, there are plugins that also allow beginners to optimize CSS and JavaScript. In our article on CSS and JavaScript optimizationwe will explain further details and introduce you to several useful plugins.

Four is a winner!

These were the four areas in which our customers were able to save a particularly large amount of loading time. With relatively little effort, you can improve your WordPress performance by caching, image optimization, optimizing CSS & JavaScript, and cleaning up WordPress.

#5 Without good hosting most measures are for nothing

The first four fields of optimization promise to reduce loading time, but can be a bit of a letdown if your hosting slows you down. By that we don't only mean the hardware requirements for WordPress, but rather certain technologies that show you that a web host allows you to optimize WordPress accordingly.

As a rule of thumb, you can remember that performant WordPress hosting should have these key data:

  • SSD hard disk
  • PHP memory limit of at least 64MB, better 128MB
  • Reliable data centers
  • Current PHP version (7.4)
  • HTTP/2 and free SSL certificate

Then there is the difference between shared hosting and separate (virtual) servers.

With shared hosting, you share the server and its computing power with other sites. Usually, a few dozen to a few hundred. If you have your own server, you don't have to share the computing power with anyone. It offers the advantage of performance security.

Although your own server does not automatically mean more performance, experience shows that especially the cheap hosting rates, which only cost a few Euros per month, cannot compete with virtual servers in terms of performance.

The finer points - less penetrating power, more effort

All performance relevant areas that I have mentioned so far can be optimized by virtually any WordPress user. Either via Plugins, simple testing or the purchase of appropriate products. It gets more complicated if you have already optimized these areas. Because then you have to go deeper into the site structure. And individual optimization measures no longer have the same penetrating power.

#6 Render blocking: Wrong loading order

One point that performance optimization tools like Google PageSpeed Insights repeatedly criticize is a loading order that blocks the rendering.

An example illustrates the problem: A slider consists of images and the animation command that makes these images rotate. If the JavaScript command is loaded first and the images at the end, then your site already has a functioning slider, but no images. So loading the site takes longer. This state can be prevented by the correct loading order.

While there are ways to optimize the loading sequence with plugins, our experience shows that these are not always able to fully optimize your site. The best results in such a case are usually achieved by a web designer who is well versed in the functions of the website.

#7 Above the Fold: Optimizing the visible area of the site

Besides the total loading time of your site perceived loading time is the key. What is meant by this is the time that a site visitor perceives as loading time. This perceived loading time can be shortened with some tricks. So a user gets the impression that it site is already completely built, although in the background is still computed.

Especially important for the optimization of this "above the fold" area is optimizing the loading order. This means that content and functions that your visitors should see on the first screen size are prioritized.

WordPress  Performance: Illustration of the "above the fold" area of raidboxes.io
The top area of raidboxes.io site visitors will see without scrolling. This is the so-called "above the fold" area. For all other information the visitor has to interact with the site and scroll.

You can achieve this, for example, by optimizing the loading sequence. But there are also plugins those that make sure that yours site loads more efficiently. And only the visible area in each case. lazy load , a3 Lazy Load are examples of such plugins. This way, the user always gets all the content he or she needs, but the page load time can still benefit from it, especially if it is image-heavysite .

#8 Cleaning up your database

Besides images and scripts, your database can also become too large. Again, there are handy tools to keep your database nice and slim. For example the plugin WP Optimization.

#9 Pingbacks and trackbacks

By default, WordPress interacts with other sites that allow pingbacks and trackbacks. Every time your site or one of your blog posts is mentioned, you will automatically be notified – and your database will be overloaded.

If you don't need this feature (the added value is negligible in my opinion) you should disable pingbacks and trackbacks. Again, the plugin WP-Optimize helps here. For the sake of completeness, it must be mentioned here that this is more of a theoretical problem. None of our customers has had any serious performance losses as a result.

#10 Prevent hotlinking

Hotlinking means that somebody links directly to an image on your server - so in the end your bandwidth is "stolen". On an Apache web server, you can prevent hotlinking by adding the following code to the .htaccess file

RewriteEngine on

RewriteCond %{HTTP_REFERER} !^$

RewriteCond %{HTTP_REFERER} !^http(s)?://(www.)?deineseite.de [NC]

RewriteCond %{HTTP_REFERER} !^http(s)?://(www.)?google.de [NC]

RewriteCond %{HTTP_REFERER} !^http(s)?://(www.)?google.com [NC]

RewriteRule .(jpg|jpeg|png|gif)$ – [NC,F,L]

To prevent hotlinking on an NGINX server, add these lines of code to your NGINX wp-config file:

location ~ .(gif|png|jpeg|jpg|svg|webp)$ {
     valid_referers none blocked server_names
	 *.example.com example.* www.example.org/galleries/ ~\.google\.;
     if ($invalid_referer) {
        return 403;
    }
}

Breakdown of the code:
location ~ .(gif|png|jpeg|jpg|svg|webp)$ {
specifies the file extensions you want to protect from hotlinking, for example, if you still want to protect pdf files, the line of code would look like this
location ~ .(gif|png|jpeg|jpg|svg|webp|pdf)$

{valid_referers none blocked server_names
*.deineseite.dedeineseite.de ~.google. ~.bing. ~.yahoo.;
These lines are a bit extensive, but it will help you better understand what can be done with this rule. These lines indicate which domains are allowed to hotlink your files. In this example yoursite.com with all subdomains, as well as Google, Bing and Yahoo.

if ($invalid_referer) {
return 403;
}
If a request comes in and the requested resource is NOT on your whitelist, the server will return a 403 (Forbidden).

No access to your wp-config?

You are wondering what you can do if your hoster doesn't allow changes to the wp-config (like for example at RAIDBOXES)? In this case, there are numerous security plugins available in the official WordPress plugin directorythat prevent hotlinking. One plugin that offers this function is for example All In One WP Security & Firewall. The plugin is active on over 800,000 WordPress sites and has an average rating of 4.8 out of 5 stars (out of almost 1,000 reviews).

"And what about CDN?"

One of the most frequently asked questions is about a CDN. For example: "Does a CDN make mine site faster for visitors in Germany?", "Why do I need a CDN?", "Would you recommend using a CDN for my blog or shop? But in most cases the answer was: No.

To make a long story short: a CDN makes the most sense if your users are geographically dispersed. For example, if you have customers in Central Europe, South America, and Australia. If your core target group is limited to one country, you can directly abandon the idea of using a CDN to optimize your WordPress performance.

The WordPress developer Ernesto Ruge by the way, wrote a very nice article which I can only recommend to you.

Conclusion: Don't be afraid of seemingly complicated optimization steps

Quite often WordPress users are afraid to make changes in those areas that are quite easy to implement and usually lead to performance improvements. Or they forget about these possibilities completely. Other areas, on the other hand, such as CDN, come up again and again during consultations, although they often have no effect on page loading time at all.

Therefore, I can only advise that you should first concentrate on the "low hanging fruits" of optimization. With relatively little effort, you can already make great progress in reducing your load time here. And that even if you are a WordPress beginner.

So don't be discouraged because of advice and suggestions by tools like PageSpeed Insights.

Because at its core, load time optimization is only about a few areas:

  • Reducing the size of your site
  • Reduction of HTTP requests
  • Compression of the individual data packets
  • Optimization of the user experience

If you have understood this, then you can effectively make use of the 10 most important levers of WordPress performance. And for more complex optimization steps, there are also experts who can bring your site performance up to scratch.

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