WordPress Caching: The Essential Guide

As a website owner, it’s crucial to understand that caching is one of the most powerful tools available. Caching can significantly boost your website’s performance and make it much faster.

A fast website leads to a positive user experience and improved SEO performance. For WordPress sites selling products or services, a faster website powered by caching tools will also help increase conversions and overall sales.

In this guide, we’ll explore what WordPress caching is, how it works, its benefits, and how to enable it. Let’s dive in.

What is WordPress caching?

WordPress caching helps your website load more quickly by reducing data transfer between the visitor’s browser, your WordPress database, and your web server. In short, caching is a critical part of WordPress optimization.

Caching can dramatically improve performance by reducing page load times. Instead of serving dynamic content with each page load, WordPress generates static HTML files for visitors. This means faster loading times and less server load.

How website caching works

The technology behind website caching might seem complicated, but the concept is simple. Here’s an analogy:

If asked to calculate 10 x 10, you instantly know the answer is 100 without thinking because you’ve done it so many times. Website caching works similarly. Instead of processing each request individually, the server recalls the final result of previous calculations.

When a visitor loads a page, your server typically:

• Generates the header and footer
• Finds sidebar widgets
• Retrieves pages and posts

With caching, the server stores these results and delivers them directly, speeding up page loads.

How cached web pages are served to users

It’s a lot easier to fully understand the process of website caching when looking at how each cached page is served to your site’s visitors.

Say that you could snap your fingers, and your site would instantly have caching enabled. The very first time a user lands on your site, they’ll be served the page or post in the way you might expect:

• The request gets received
• The request is processed on your server
• The page or post is translated into an HTML file that’s delivered to the user’s browser

But remember, you have WordPress caching turned on. This means that your server will automatically store this particular HTML file inside of its RAM (random access memory), which is lightning-fast.

After this is done, every time any other user views this particular page or post, your server doesn’t need to process the request and convert it into a deliverable HTML file. Rather, the server sends the HTML file that it prepared from the prior request, directly to the new user’s browser.

All of the time needed for your server to process the full page-load request has now been eliminated due to website caching.

Benefits of WordPress caching

We’ve discussed how caching works, but what does it all mean? Caching your WordPress website can have a significant and positive impact on performance. It allows your website to quickly deliver content, leading to several benefits for you. 

Improved user experience 

When you click a link or visit a website, you probably expect the page to load as quickly as possible. Your users have the same expectations for your website; content should be presented in less than a few seconds. If it takes too long, users may exit out of the page or get frustrated. 

Caching your website avoids this situation. Instead, pages and content will load much faster and keep website visitors satisfied. This means users will stay on the site longer, potentially making a purchase or increasing conversions. 

Higher rankings on Google 

You want your website to be seen by Google and other search engines so your customers can actually find you. This is where search engine optimization (SEO) comes in. 

Google uses three different metrics to evaluate a website and its ranking potential. These metrics, referred to as your Core Web Vitals, focus on three measurements: 

• Largest Contentful Paint (LCP): Measures loading performance
• Interaction To Next Paint (INP): Measures responsiveness 
• Cumulative Layout Shift (CLS): Measures visual stability 

Optimizing these metrics impacts your rankings, page experience, and SEO performance directly. Google even states that good page experiences are rewarded, and it’s recommended that site owners prioritize good Core Web Vitals: 

“Core Web Vitals are used by our ranking systems. We recommend site owners achieve good Core Web Vitals for success with Search and to ensure a great user experience generally.”

Google

While your WordPress theme, creative assets, and scripts have the largest impact on your Core Web Vitals, the first metric (Largest Contentful Paint) can be improved with caching. 

Client satisfaction 

If you build and maintain websites for clients, you can take these benefits a step further. Show your client how you are continuously improving their website performance and speed. This process can be done by checking their website in PageSpeed Insights by Google before and after implementing a caching plugin. A plugin like Solid Performance can provide instant improvements, making it a simple way to demonstrate success. 

In addition, show your client how you boost their SEO rankings or even conversions. You’ll be able to meet a widely accepted expectation that well-run sites do not have slow download or content delivery times.

With caching, you’ll shave off additional load times that can be the difference between a new customer or a bounced visitor. If your site consistently delivers pages at higher than a two to three-second load time, you could easily be losing almost half of your potential traffic and, more importantly, customers.

WordPress caching types 

Generally speaking, there are two different cache types:

1. Browser caching – Performed on the user’s (or client’s) end.
2. Server caching – Performed on the website host’s server.

Since we’re talking about WordPress specifically, we’ll also cover different WordPress-related caching types, including:

• Page caching
• Database caching (object cache)
• Opcode caching

Browser caching

Browser caching is the most common form of caching. It works by storing the content and assets of a site in the browser’s memory for subsequent visits until that user clears their cache. Browser caching may not be great for dynamic websites (after all, you don’t want users sharing shopping carts), but it’s great for content-based websites. 

Here’s how browser caching works: When you land on a site you want to view, your device doesn’t only need to retrieve the page content. It also needs to retrieve other resources like:

• WordPress CSS Stylesheets
• WordPress Javascript files
• Website fonts

Your device’s browser downloads all of this information, along with the page contents.

Localized browser caching directs your web browser to save all of these files for a period of time. It won’t need to pull them off the server again the next time you land on the site.

As an example, the first time you click on our homepage, our server will send your browser tons of resources that it will cache. The first visit to our homepage might take a couple of seconds to fully download, but when you return to it you’ll notice that it will load much faster.

Often, browser caching alone can increase page load speeds by a full second or more.

Server caching

At the beginning of this article, we covered how server caching works and the mechanisms that run it. Remember, rather than processing every browser request individually, the server compiles the results of those individual requests into its RAM.

The server then delivers those results in the form of an HTML file that allows your site to perform better, load faster, and run at its absolute best.

However, one key aspect of server caching that we haven’t discussed is the difference between full-page cache and object cache. An object cache only stores bits of data, rather than the entire page. Object caching works well within website code. It can be used to store the results of more complicated operations like navigation menu generation.

Page caching

One of the fastest ways to speed up your WordPress website is with page caching. It works by storing the code of your WordPress URLs in a secure directory. Then, when visitors arrive on your website, the browser doesn’t run through PHP or hit your database again. Instead, it just serves the static HTML, CSS, and JS files quickly. 

Usually, this method of caching requires at least one person to visit your site so the cache can be generated. So, one user may experience a slower page load time, but all visitors after that will have the faster, improved experience. 

Solid Performance focuses exclusively on page caching, grabbing the HTML of your WordPress URLs and storing that in a secure directory. Then, when your visitors arrive at your site, the browser doesn’t need to run through PHP or hit your database again, it just serves up the static HTML, CSS, and JS files fast and simply.  

Database caching (object cache)

Database caching, which is also known as object caching, is an advanced form of website caching that involves caching the request of a query so that the information doesn’t have to be looked up each time from your WordPress database.

It’s worth noting that database caching is a more advanced form of WordPress caching, and unless you’re a WordPress developer, you don’t need to worry about this. 

Opcode caching 

WordPress is primarily built using the PHP programming language. Every time a visitor requests a page, the PHP code is run, compiled, and sent to the server for processing and display. 

Opcode caching is an advanced form of caching that effectively prevents the code from having to be re-compiled every time it’s requested (i.e., the compiled code is saved). 

Overall, it’s very advanced. Unless you have a website serving hundreds of thousands of unique visitors and you’re looking to speed it up, you don’t really need to worry about this type of caching, either. 

How do I enable caching in WordPress?

Caching can be easily enabled on your WordPress website with a plugin. 

The very first thing you need to know about using caching plugins is to never use more than one single caching plugin simultaneously. Using more than one caching plugin will not increase the speed of your site. In fact, it will probably slow down your site by a lot. You could even break your site completely by using multiple caching plugins.

Instead, choose a single plugin for caching and make sure it’s correctly configured. Once it is, it will noticeably speed up your website. 

We recommend trying Solid Performance. It’s a simple yet powerful caching solution for any WordPress website. With a few clicks, your site’s performance will be quicker. It also reduces server load, boosts your Core Web Vitals, and gives you flexibility for key tasks. Plus, it’s free! Try it out on your site now.    

Tips for WordPress developers

If you’re not much of a coder, you can probably skip over this section. But if you code, you know how important efficient code is for running a properly cached website.

The first thing to know about coding within the WordPress platform is the way WordPress works behind the scenes.

When getting metadata for a particular post, you’ll call get_post_meta( $post_id, ‘co-author’, true ); WordPress will retrieve all of the metadata for the post. As such, having 40 different get_post_meta() calls in order to retrieve the data of one post isn’t wasteful.

Efficient code requires that transients within WordPress are used the right way. A transient is a type of object-caching solution that has a date of expiration.

They can be used to cache site headers or footers, which typically don’t change much over time. When they do change, all you’ll need to do is empty out the cache.

Is page caching alone enough?

Page caching is a powerful and simple way to improve your site’s performance. However, there are other factors that affect your site’s speed, SEO rankings, and user experience. In addition to using the Solid Performance plugin or implementing page caching, we recommend doing the following: 

• Use quality themes and plugins. WordPress plugins and themes can sometimes cause conflicts due to the code they use. This can ultimately lead to slower page loads if the theme or plugin was not built using WordPress development best practices or outdated code libraries. Using quality themes and plugins relates to WordPress security, too, as you’ll want to avoid harmful nulled plugins and themes. 
• Optimize your images and media. Images can take time to load on a website, so try to compress them with a WordPress plugin. Use the smallest possible images and formats like WebP for images and SVG for logos and graphics. 
• Choose a reliable host. Your hosting provider and plan may impact your site’s performance, so choose one that offers performance features. If your website is very dynamic, you may want to consider a dedicated hosting plan or Virtual Private Server (VPS) hosting instead of shared hosting. 
• Use the latest PHP version. Your hosting provider should be running the latest version of PHP, but you can check what version your site is using by going to your admin dashboard and navigating to Tools > Site Health > Info. If it needs to be updated, contact your hosting provider or find the settings in your hosting dashboard. The current version is PHP 8.3, but any version above 8.0 is ideal. 
• Use lazy loading. If you use a lot of images or other media, consider lazy loading. Lazy loading only downloads images and videos visible on the user’s screen. As users scroll, more images can be loaded. You can enable lazy loading using a WordPress plugin like Optimole. 

Improve your WordPress website today 

Site caching technology is the best way to increase your website’s speed without sacrificing content or other performance factors. When properly implemented, WordPress caching will result in much faster load times for your users while decreasing overall server load.

If you’re not caching your WordPress site already, it’s definitely time to get started. Download Solid Performance, a simple and powerful caching solution for WordPress sites. You’ll give your website and Core Web Vitals a boost, provide a better user experience, and make your clients happy! Try it now for free.