You will agree that no one likes a slow site. A visitor will never fully browse your website if it loads with the speed of a turtle at the gallop.

WordPress powers more than 28 percent of the entire web. There are a number of techniques to speed up a WordPress website and one of them is cache.

Every time a visitor visits a site, your browser sends a request to the website server and the server responds accordingly. But, if a website has a mix of dynamic and static data to display, it will take more time to get a response from the server. This increases the server response time resulting in longer page loading times.

Browsers spend almost 80 percent of the time fetching components including images, stylesheets, and scripts. Reducing the number of requests helps in reducing server response time.

Static content always loads faster than the dynamic content. How about the idea to separate static from the dynamic one? This is where cache comes in handy. Cache is the data that is usually stored on the user’s machine. Most of the time, it includes the static data that does not change rapidly like images, CSS, JS, and HTML files. So that, whenever a returning visitor’s browser sends a request, the static data is loaded via the cache, and the dynamic data will be served by the server. In this way, you can reduce the number of requests sent to the server so that the visitor could get better page load times.

In many cases, the cache can be stored on the server as well.

There are a number of caching techniques that can be used to speed up a WordPress site. Almost all the caching plugins are using the below basic techniques.

Browser Caching

Browser cache is the temporary storage of the files downloaded by the browsers. When a visitor revisits the site, the browser checks which content has been updated and requests the server for updated content only.

This helps in reducing the number of HTTP requests and saves bandwidth, which results in a faster web page loading experience.

Gzip Components

Gzip is considered as the most effective compression method at this time. It provides a lossless compression mechanism that means the original data can be recovered while decompressing.

It replaces the repeated strings in response with a reference code to reduce the response size and then decompressed by the browser. The lower the file size means an increase in the performance.

Put Stylesheets on the Top

Visuals are an important element of a website. It is always suggested to keep the stylesheets in the HEAD of a page as they are static files and can load quickly. This kind of technique is called Progressive Rendering in which the content is rendered to display as quickly as possible.

This improves the overall user experience and the visitor does not lose interest while the rest of the page is being loaded.

Put Scripts at the Bottom

When a visitor visits a web page, the HTML starts streaming to the web browser. And when a browser encounters a tag for an external source of an image, script, or CSS file; it will start downloading that file at the same time.

If the scripts are at the bottom of a page, they will be loaded last. The above-loaded elements ensure there is something to show up in the browser faster before the visitor lose his interest. This can improve the overall user experience.

Minify JavaScript and CSS

Minification is the practice to reduce the file size of HTML, CSS and JavaScript files by removing the unnecessary characters from the code like comments, new line, white spacing etc. thereby improve load times. Although minification helps in increasing the performance of a web page, it can also break the CSS of a site. However, it is always suggested to test minification on a staging site first before applying it to a live site.

Combine CSS and JavaScript Files

If you have a number of JavaScript files, combine them into a single JS file. This will generate only one request to the server rather than send requests equalling to the number of JS files. Similarly for CSS files, combine all CSS files into one file.

Use a Content Delivery Network (CDN)

Assume, your WordPress site has a global audience and its data centre is located in the UK or Europe. When a visitor visits the site from elsewhere, the request is sent to the server, then the server processes the request and responds to it accordingly. The longer the distance between the visitor and the server, the more delay in loading a web page.

This is where a CDN turns out to be useful.

A CDN is a collection of web servers distributed across multiple geographical locations to deliver the content requesting from those locations. It caches and distributes the content of WordPress site across its network for faster delivery without affecting the server.

Here are the most widely used, top-rated WordPress caching plugins.

WP Rocket
WP Super Cache
WP Fastest Cache
W3 Total Cache

Each plugin has its own set of features that separate them from one another. The choice of a good plugin should be based on your requirements, level of expertise and of course the budget.

If you don’t want to spend money, then the free version of WP Fastest Cache is probably the best and easiest to set up.

You can check your web speed using these tools.

https://tools.pingdom.com
and
https://developers.google.com/speed/pagespeed/insights/