What Is Full-Page Caching? (And Why Rocket Does It Better)

What Is Full-Page Caching? (And Why Rocket Does It Better)
  • 9 min read

If you’re talking about a cache in the world of the Internet, then you’re probably not talking about a cache of loot. A cache is a kind of buffer or intermediate stage of data storage. If a website has a cache, then we’re talking about a kind of virtual buffer in which data is stored.

Beyond excellent customer support that we’re so well known for, Rocket is all about our obsession over fast WordPress hosting powered by Cloudflare Enterprise with full-page caching built by a veteran team of industry experts.

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The advantage of a website cache is that temporarily stored data (data in the cache) can be retrieved much faster, which leads to a significant increase in the performance of a website. Loading time and user experience are considerably improved when a website uses some level of caching.

Why is this of any importance? Well, on the one hand, fast-loading web pages are essential so visitors stay on the page and don’t bounce. On the other hand, loading speed is a ranking factor for Google. 

In a nutshell, speed wins. People are happier using fast websites, and fast websites have a higher conversion rate than slow websites.

Speed is so important for a website because you want to attract and retain potential customers. And you want them to tell their friends. What keeps people from staying on your site – and converting – is a poor website experience.

Full-page caching is a more advanced form of caching so to understand full-page caching let’s begin with normal caching and build from there.

What is Caching?

Want a fast website? Enter Caching.

Website caching and full-page caching are techniques to speed up the load time of websites. It’s common practice used almost everywhere because of the massive gains it brings to website performance. Caching works by making the webserver more efficient at doing its job.

“At the end of the day, WordPress is a Content Management System that people use to build a website that ultimately spits out HTML/CSS/JS/ and images to construct the website. Each and every asset is cacheable in some form, effectively allowing us to deliver said website as close as physically possible to the visitor vs having to proxy back to a single location.”


What is Full-Page Caching in WordPress?

If you’re concerned with the loading speed of your customer’s websites — or your own — you can’t avoid the cache. 

Caching is about having a fast buffer memory that avoids repeated accesses to slower media thus reducing the loading time of a website. This can be done at the hardware level as well as in software as temporary files or reserved memory. Rocket has put all of this together to provide the best full-page caching content delivery solution in the world.

WordPress works with no less than six different caching levels.

Opcode Cache

If you imagine the caching elements of WordPress like a pyramid, Opcode forms the top. PHP code is understandable to humans but needs to be converted to machine code, or bytecode, in order to be processed by a computer. Opcode stores this bytecode and has been integrated as standard since way back in PHP 5.5.

Object Cache

WordPress installations work with MySQL databases. These resource hogs perform numerous queries on each retrieval. Many of these queries can be stored in the object cache, which improves the loading speed sustainably.

HTTP Accelerator

This stage elevates Full Page Cache to a completely new level. Said HTML versions are usually stored on hard disks. Read and write accesses, even on SSD, are slower than in-memory accesses on RAM storage. Varnish and FastCGI with Nginx can meet these RAM demands.

Browser Cache

The cache classic is the basic function on any terminal device: browsers can store queried data in varying amounts and durations. Static files that are rarely updated — CSS, JavaScript, images and fonts are best suited for the browser cache.


Although the Internet operates globally, comparatively local nodes can speed up page retrieval. A content delivery network (CDN), like Cloudflare, consists of a series of servers distributed around the world. When a website is visited, static data is retrieved from the nearest servers.

“A CDN provider will place servers in many locations, but some of the most important is the connection points at the edge between different networks. CDN edge servers store (cache) content in strategic locations in order to take the load off of one or more origin servers.”


CDN Spotlight: Why Cloudflare Full Page Caching From The Edge is so Powerful

A content delivery network (CDN) is a group of proxy servers and data centers distributed worldwide. As content is delivered through a particular server, that content is cached, allowing it to be delivered more quickly, no matter where your website is accessed in the world. What makes Rocket.net different is that our platform is powered by Cloudflare Enterprise CDN – not just out-of-the-box Cloudflare.

This means that since our platform’s WordPress servers are strategically placed around the world, your customers access your eCommerce site from the server physically located closest to them. Shorter distances mean faster load times.

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Simply stated,Rocket.net helps your WordPress website and WooCommerce online shop benefit immediately.

  • That means your website is instantly pre-configured.
  • Your boosted website speed delivers better SEO ranking and higher conversions.
  • And with our globally cached, hacker-proof hosting your website is always open for business.

Is Rocket’s CDN compatible with my caching plugin?

Yes! We are compatible with every plugin under the sun. You do not need to make any changes to your site and/or future workflows as we will work with everything. Which is just being smart.

In fact, our Smart Caching gives us the ability to treat every asset in our cache in a specific way. Prior to Smart Caching, our CDN cache purge function would attempt to purge all of those pages but would run into limitations on the CDN purge. Smart Caching will only purge HTML assets. This means that your CSS, JS, and images all stay nice and warm in the cache.

Full Page Cache

On every website, there are pages, or parts of pages — for example, headers, footers, product descriptions, etc. — that rarely or never change. Full Page Cache creates an HTML version of these items instead of performing a much more time-consuming PHP query each time.

What Does Full Page Caching Do?

Full page caching improves response time while reducing the load on your server. Without caching, each page is going to retrieve information from the database. Full-page caching means a fully-generated page can be read directly from the cache.

Let’s see Caching in action.

Joe’s Auto-Parts Shop – A Static Web Site

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Imagine Joe. He’s a guy that owns and runs a large warehouse full of car parts. At the front of the warehouse is a counter where customers arrive to buy his parts. When a customer arrives to buy some parts the transaction follows this procedure:

  1. The customer hands Joe a list of car parts.
  2. Joe fetches the 1st part and puts it on the counter.
  3. Joe fetches the 2nd part and puts it on the counter.
  4. And so on until the end of the list.
  5. The customer pays and leaves.

So how does this apply to a static website?

A static website is one that does not use any databases, PHP scripts, or any other programs. Think of a simple website that is only HTML pages and images. Joe and his warehouse represent the parts of this simple website like this:

  • The warehouse is the physical server.
  • Joe is the webserver software e.g. Apache
  • The car parts are the files that make up a website e.g. images and HTML files.

The procedure for serving this simple site is:

  1. A browser requests a web page from Apache running on the server.
  2. Apache reads the 1st file from the disk and sends it to the browser.
  3. Apache reads the 2nd file from the disk and sends it to the browser.
  4. And so on until it has fetched everything.
  5. The browser displays the completed webpage.

This setup works fine for small websites but quickly fails under pressure.

Joe Gets Busy – Caching Saves The Day

Joe’s system works well until he starts to get busy. So busy in fact that he is spending most of his time walking from the counter and into the warehouse that and he can’t keep up with all the new customers.

Joe could buy an extra warehouse and employ someone else to work there to meet the extra demand. But this is costly and doesn’t maximize the resources he already has. Instead, Joe thinks about how he could make his process more efficient in the warehouse he has.

Joe realizes that 90% of the parts he is fetching for customers are one of only 10. So he decides to keep those 10 parts under the counter where he can grab them straight away when someone asks for them. He can now serve the majority of customer requests straight from the counter without a trip into the warehouse. This is much faster.

Caching does something very similar on a webserver. Just like Joe’s walk back into the warehouse, the slowest action when serving static files is loading the file from the storage device. What caching does is to keep the most frequently requested files in RAM where they can be accessed thousands of times faster than reading them from storage.

This type of caching works great for images and other static files but WordPress is a dynamic website with PHP scripts and database.

Enter full-page caching.

Joe’s Life Gets Complicated – PHP, Databases, and Caching

A new Toyota workshop opens in the same town as Joe and they use Joe to supply the spare parts. This is great for Joe except for one problem, Toyota only order parts by their Toyota part number. They give Joe a huge catalog so he can look up the Toyota part numbers and match them to the parts in his warehouse whenever he receives an order from them.

But this makes Joe slow again.

Anytime he has to look up the Toyota part in the catalog it takes him a long time. Even if it’s one of the parts under the counter he can’t just reach for it because he first has to lookup the Toyota part number in the catalog. His old system of keeping the 10 most requested parts under the counter is still helping but the new catalog lookups are now the big bottleneck.

Joe thinks about this again and comes up with a solution. He notices that most of the Toyota orders are one of only a small group. So he writes out a cheat sheet of the most common Toyota part numbers and their corresponding parts and he tapes it to the countertop.

Now he doesn’t need to use the catalog for most of the Toyota orders, he can glance at the cheatsheet and convert the Toyota part number almost instantly into a part he can fetch.

WordPress sites have a similar problem to Joe. WordPress builds every webpage when it is requested by the browser. The HTML pages that your browser loads don’t exist until you ask WordPress for them.

This is how WordPress creates a page of your site:

  1. A browser requests a web page from WordPress.
  2. A PHP script accepts the request and queries the database for what it needs to build the page.
  3. The database looks up and returns all the information to the PHP process.
  4. The PHP script builds the page with that information and sends it to the browser.

This is a lot of work and is the reason that non-cached WordPress websites need many times more computer resources than static websites.

Just like Joe, your WordPress site receives requests for the same pages very often, such as the landing page for your site as this page gets served every time a new visitor arrives. In a non-caches setup, WordPress has to process this request with PHP scrips and make database queries for every visitor even though it creates the exact same page every time.

This makes for a great deal of duplicated work.

Full-page caching solves this problem. It notices that a certain request and the page that gets generated are always the same so it caches a copy of the page in RAM. It also keeps a cheat sheet of the requests that created those pages so when a visitor requests a page that it generated before it serves it directly from RAM rather than re-create it.

This significantly reduces the workload of the webserver by bypassing many PHP processes and database lookups and by serving previously generated pages directly from RAM. This can give you a dynamic WordPress website that is almost as efficient as a static website.

Caching and full-page caching are superb technologies that leverage the resources of your webserver to maximize the efficiency of your webserver and give you a snappy WordPress site.

How Full-Page Caching Helps With Core Web Vitals?

You’ve by now gotten your hands dirty with Google Core Vitals, right? In addition to Google Core Web Vitals, Google is measuring a growing number of user-centric response metrics, including Interaction to Next Paint (INP) and Time to First Byte (TTFB). Full page caching impacts TTFB big time.

Compiling dynamic content takes time for each request. Cache plugins allow content to be cached as static HTML pages. This saves valuable milliseconds every time. WordPress caching plugins improve performance significantly. Static content should also be ready in the cache so that it is not reloaded with every request.

One of the easiest and best ways to reduce TTFB, and speed up your website in general, is by setting up a caching layer such as a full page cache.

The significance of TTFB is it’s the most important metric that nobody thinks of for Core Web Vitals and, in effect, the most important metric for your websites. Why? In a nutshell, people are impatient.

If people aren’t waiting for your websites to load, they are leaving — and your clients have lost them as customers. You don’t even know how many you’ve lost or if they’ll ever come back. 

Cache it, or lose it. It’s that simple.

Talk Is Cheap. Let Rocket Show You What The Fastest WordPress Hosting REALLY Means!

Unhappy with the speed of your WordPress website? Let’s talk about how we can migrate your site to Rocket.net, the fastest WordPress hosting available anywhere.

Our team of experts are standing by. Most website owners have switched hosting providers multiple times over the history of their site. We’re confident that you won’t look back once you make the switch to Rocket.net. 

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