Caching is one of the most effective ways to make your website faster, but it remains a vague concept for many people. In short: caching ensures that frequently requested data is temporarily stored, so your website doesn’t have to rebuild everything over and over again. This article explains exactly what browser cache and server cache are, how they work together, and how to set them up so visitors are served faster.
What exactly is caching?
Every time someone visits your website, the server has to look up files, perform calculations, and build a page that is sent to the browser. For a dynamic website like WordPress, this often happens with the help of a database, which takes time. Caching stores the result of that process (temporarily), so that the next time it’s directly ready without everything needing to be rebuilt.
You can apply caching at multiple levels: in the visitor’s browser, on the server itself, and sometimes even somewhere in between with a CDN. Each level solves a different part of the problem, and together they ensure noticeably faster loading times.
Caching temporarily stores requested pages, so the server has to do less work.
Browser cache versus server cache
Browser cache works on the visitor’s side. When someone visits your website, the browser stores files such as images, CSS, and JavaScript locally. On a subsequent visit, these files don’t need to be downloaded again, making the page visible almost instantly. You determine via headers how long the browser is allowed to keep these files before fetching them again.
Server cache works on the other side: on the server itself. Instead of rebuilding a complete WordPress page with database requests on every visit, a ready-made version of the page is stored. That version is shown to new visitors until the page changes or the cache expires. This saves a lot of server load, especially for websites with many simultaneous visitors.
Setting up caching for your website
How you set up caching depends on the type of website you have. For WordPress, a caching plugin is the most common solution. For a static website or custom application, you usually set up caching via server configuration or in Plesk.
Choose a caching method
For WordPress, use a caching plugin that fits your server environment, for example a plugin that works specifically with LiteSpeed servers.
Set browser cache headers
In Plesk, you can set expiration times for static files under your domain settings, so browsers keep them longer.
Activate server caching
Enable the caching plugin or server setting and check whether pages are actually served as “cached”, for example via your browser’s developer tools.
Set up cache expiration on changes
Make sure the cache is automatically cleared as soon as you edit content, so visitors always see the current version of the page.
For a good caching strategy, it’s important that your website runs on a server suited for it. Check out the options for web hosting with LiteSpeed and NVMe storage, which makes caching even more effective.
Common mistakes with caching
A common problem is that visitors see outdated content because the cache isn’t automatically refreshed after a change. This often happens with webshops, where stock or price changes aren’t immediately visible to visitors. Therefore, make sure your caching plugin is properly configured to exclude important pages such as the shopping cart and checkout from caching.
Another mistake is setting browser cache times too aggressively for files that change regularly, such as CSS or JavaScript after a theme update. As a result, visitors keep seeing an old version of your website until their browser cache expires. Use version numbers or file names that change with an update, so the browser automatically fetches the new version.
Finally, caching is sometimes confused with other speed optimizations, such as compressing images or minifying code. Caching solves the problem of repeated server load, but it’s not a substitute for an overall technical check of your website.
Frequently asked questions
Does caching also work for a webshop?
Yes, but with exceptions. Pages such as the shopping cart, checkout, and customer account usually need to be excluded from caching, because they show personal or real-time data.
Can caching cause changes to not be visible?
Yes, that’s a known side effect. If the cache isn’t automatically refreshed after a change, visitors may temporarily see an old version of the page until the cache expires or is manually cleared.
Do I also need a CDN in addition to caching?
Not necessarily. Caching mainly solves the server load issue, while a CDN reduces the distance between visitor and server. They can perfectly well be used alongside each other, but caching alone often already delivers a noticeable speed gain.
Conclusion
Caching ensures that your website has to do less work on every visit, resulting in faster loading times and less server load. By properly aligning browser cache and server cache, and setting up exceptions for dynamic pages, you get the most out of your website without visitors seeing outdated content.