A Guide to WordPress Speed & Importance of Cache

It is the era of speed and WordPress!

You will agree that no one likes a slow site. A visitor will never spend more than three seconds on a site, if it loads with the speed of a turtle gallop.

The search engine giant, Google, ranks sites loaded under two seconds in its search engine results pages (SERPs) and WordPress powers of more than 28 percent of the entire web. There are a number of techniques to speed up a WordPress site and one of them is cache.

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

Browsers spend almost 80 percent of the time fetching components including images, stylesheets, and scripts. Reducing the number of HTTP 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 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 request 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 as 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 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 in the 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, but 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 Content Delivery Network (CDN)

Assume, your WordPress site has a global audience and its data center is located in US. For example, when a visitor visits the site from another corner of the world, the request is sent to the server, then the server processes request and respond 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 turn out to be useful.

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

Varnish Cache

Varnish Cache is a web application accelerator that is also known as caching HTTP reverse proxy. To understand the process of Varnish, let’s take an example when a visitor visits a blog post, the blog contents are extracted from the database, merged with a template, processed in many ways, and then returned to the server, which sends the end result back to the requested browser.

Next time, a request for that content arrives from the same visitor, Varnish Cache will simply send the copy it already has in the memory. The server, database, and all other processes aren’t involved at all. Thus, this will dramatically improve the page load performance without keeping the server busy.

Wrapping Up!

So, I have talked enough about the caching techniques that most of the WordPress cache plugins are using. But, everyone have their own mechanism and configurations to make a WordPress site faster.

Here are the most widely used, top-rated WordPress caching plugins that are playing their part to contribute to the world of WordPress.

1. WP Rocket
2. WP Super Cache
3. WP Fastest Cache
4. W3 Total Cache

As I said, every 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.

It is always suggested to keep an eye on the new plugins adding to the WordPress repository. It is worth mentioning that folks at Cloudways launched a WordPress caching plugin called as Breeze in response to their customer’s feedback.

Breeze is an easy to use and free WordPress cache plugin. Besides caching, it also offers CDN integration, Varnish and optimizing the database. Cloudways claims that a WordPress site hosted via Cloudways with integrated Breeze can be loaded in just 143 ms.

I would be interested to know which plugins you have experienced with. And what best suited you? That’s all!