Author: Emman Zahid

In case you might be questioning yourself:

“I want to cache my WordPress site. What type of caching should I use for it?”

The answer involves many options, depending on the nature of your website and what you want to achieve from it.

There are several types of caching, each of which is different from the others and useful in different circumstances. So it’s essential to comprehend the kinds of data they store and the levels of control they provide you.

In this article, we’ll discuss different types of web cache in detail, how they work, and their differences.

Then we’ll look at various types of content that can be cached and how you can cache your WordPress site in the most efficient way possible! 

What Are The Caching Types?

There are two types of caching options you can go with:

1. Server-side Caching
2. Client-side Caching

Although both of them cache your website differently but has one similar goal:

Making your website load blazing fast without loading the entire site files again.

Let’s take a closer look at both of them. 

What’s Server-Side Caching?

Server-side caching temporarily stores web files and data on the server for later use, effectively reducing the server’s load and latency.

Here’s how it works:

1. When the user visits a website and requests the web page, the website retrieves data from the server, generates that webpage, and displays it to the user.

2. After the response has been sent back to the user, the server creates a copy of the webpage and stores it as a cache.

The result? 

The next time a user revisits the website, instead of going through the whole process again, it displays the already saved (or cached) copy of the webpage – thus making the website load faster!

What’s Client-Side Caching?

Client-side caching, often called browser caching, temporarily stores the copy of a webpage in the browser’s memory (a folder created by the browser). 

So, the next time a user revisits a website with client-side caching enabled, it won’t make a call to the server for the data. Instead, it will fetch it from the browser cache folder located on the user’s device.

Server-Side Caching vs. Client-Side Caching

The type of caching you choose significantly improves the overall user experience and usability of your WordPress site. So it’s always better to understand which type goes well with your website beforehand.

Let us help you figure that out with an example:

Suppose you run an online retail site.

Because of the nature of the business, the type of content on your website is dynamic (i.e., users see recommended products, emails about abandoned carts, or ads for similar/relevant products).

Due to this, users access your website smoothly whenever there’s a new update. 

If your website takes longer to load, it will urge the users to move on to another site even before the content fully loads. Hence, resulting in increased bounce rates and, most importantly, a negative first impression on a visitor landing on your website.

Now, consider the above example:

• If you use server-side caching:

When the user requests a web page, the website retrieves data from the server. But before that, it checks if a copy of that web page is cached. If it’s cached, it serves the cached copy of the webpage.

There are three main scenarios:

1. If your website’s content is static, it does require any accommodation.

2. If the content is dynamic within a time frame (short-lived content), it requires cache renewal after a certain amount of time or “ajaxifying” the dynamic content.

3. On the other hand, if your website’s content is dynamic with a short time frame and is user-specific (logged-in experience, for example), it requires bypassing the cache.

By default, and if the webpage is cached, it will be served from the cache as long as there is no instruction to bypass it (i.e., adding items to the cart in some specific cases).

But there’s one problem.

It displays the cached version as if the content on the website is static!

Due to this reason:

Server-side caching is the best choice for websites with static content and short-lived cache, as it significantly reduces the number of operations on the server – without having it reconstruct the entire content per user request. On the other hand, a highly dynamic server cache is still possible using advanced technologies like Edge Side Includes (ESI) or Ajax (Asynchronous JavaScript and XML).

• Let’s try it out with client-side caching:

When you use client-side caching, the website’s copy is stored in the browser’s cache. So when the user requests a web page, it displays the cached version stored in the browser instead of requesting it from the server.

For this example, since your website has dynamic features, your preferred method will be using JavaScript (JS). It operates on the browser’s side, so you can rely on it by running the scripts within the browser to handle the dynamic needs of your website in real time.

Due to this reason:

For dynamic websites, client-side caching solves both latency and server cache problems by reducing the server load.

Now, if we categorize it further, some of the types of web cache include:

• Site (Page) Cache
• Server Cache
• Proxy Cache
• Browser Cache

However, there’s also a different type of caching unrelated to the other four types mentioned above, known as Object Cache.

Object Cache is a process that stores database query results so that they can be accessed easily the next time a user requests it. The cached object will be served instantly from the cache without needing to query the database repeatedly.

If you want to learn more about Object Cache, check out What is Object Caching and How to Use It With WordPress.

What is Site (Page) Cache?

Site cache, also known as HTTP or page cache, temporarily stores the content on your website the first time you visit it. 

So the next time you visit that website, it fetches the stored data from the site cache to display static web content faster than it would with a new request.

In addition to that:

All the data is stored in the server’s hard disk or memory (RAM), and you, as a website owner, can determine how much time a file stays in the site cache. 

If elements of your website are static, you can set a file’s expiry date for longer. However, dynamic elements of a website have much shorter expiry dates. These brief expiry dates tell the website when to refresh the files stored in your device’s site cache.

What is Browser Cache?

Browser cache stores cached versions of the specific web pages a user browses. It is built into your web browser – enabling the website to load faster in order to provide you with a better user experience.

Browser caches work by temporarily saving copies of a website’s files, such as:

• HTML pages
• Multimedia content and images
• CSS stylesheets
• JavaScript scripts

When the user revisits your website, their browser will fetch the cached files and use them to assemble your website’s content to create a smooth browsing experience. Cached content loads faster because your browser doesn’t have to load everything from scratch to display them.

Usually, a browser stores its cache for a limited time or until it is full. After that, it automatically clears out the cache and displays the updated website’s content on the next visit.

The silver lining is:

You can also delete your browser cache by manually clearing your browsing data if it takes up too much space – and that’s one of the key features of this type of cache!

In Google Chrome, you can do this by clicking:

Settings > Privacy and security > Clear browsing data

When you visit a website after clearing browser data, it will load everything from scratch.

What is Server Cache?

Server cache is also the type of web caching over which the end users don’t have any control and is fully administered by the server.

(Note: There are mainly four types of web servers – Apache, IIS, Nginx, and LiteSpeed.)

This type of cache is mainly used to reduce server loads.

When a user visits a website and requests a web page from the server, the server scans the cache and displays the stored content immediately. This helps decrease the processing time and return web pages faster, which is especially beneficial for websites with high traffic.

Server cache can be considered an umbrella term for many types of caches. The most common are:

• Object cache – stores database queries in a server-side cache for quick retrieval and prompter page loading without querying the database repeatedly.

• Opcode cache – store precompiled PHP code for speedier execution.

What is Proxy Cache?

Proxy cache stores content on the proxy server, allowing web services to share those resources with more users. The proxy server coordinates with the origin server to cache website data such as files, images, and web pages.

When a user opens a web page, the proxy checks whether it has a recent copy of that web page and its assets. 

If a copy exists, it immediately displays that web page or resource to the user. On the other hand, if the web page is old or missing, it fetches a new copy from the source, caches it to the proxy, and delivers it to the user.

Once a proxy updates a web page, it resets the webpage’s expiration date to prevent it from being labeled as outdated. The webpage will be delivered until a specific time passes, after which the proxy server will re-check the source.

Besides that, the proxy cache also has a type known as:

Content Delivery Network (CDN) cache – a cluster of servers located at different geographic locations. The server closest to the end user will return cached content to load content faster.

Site Cache vs. Browser Cache vs. Server Cache vs. Proxy Cache

Now that we know about each type of cache – let’s understand the differences between them:

Site Cache:

• Saves content like web pages, images, text, etc.
• Serves content much quicker after the first visit.
• Ideal for websites with static content.

Browser Cache:

• Stores limited data types like HTML pages, CSS stylesheets, JavaScript scripts, Images, and other multimedia files.
• Files are heavier and take time to load – thus, stored in the computer.
• Controlled by the user’s browser.
• Serves web pages directly without processing from the server.

Server Cache:

• Saves content, code, queries, and similar data on a server.
• Type of server-side caching.
• Controlled by the server.
• Administered by website owners without any input from end-users.
• Best for high-traffic websites that need to reduce server strain.

Proxy Cache:

• Allows web services to share resources with multiple users
• Saves bandwidth and decreases the loading time
• It might help in more complex scenarios, such as handling dynamic or frequently-updated resources (but only when using geotargeted content where the country/region-specific content is stored separately).

What Content Can Be Cached?

There are various types of content that website owners frequently cache. However, some can be cached, but many site owners do not cache them as it seems “risky”. And lastly, there are some which should not be cached at all.

Let’s look into all of them.

Files that can be cached but rarely cached include:

• Pages with dynamic content
• Ajax/REST requests if their cache is purged
• Other code that needs to change less frequently

Files that are frequently cached and should be cached include:

Pages with static content or types of content that remain the same for all users and don’t often change, such as

• Static images
• Logos and assets
• CSS stylesheets
• Downloadable files or other content

Files that should not be cached include:

• Dynamic content, or in simpler terms, personalized data using conditions to be displayed
• Any sensitive data (such as credit card information)

Caching with WP Rocket

WP Rocket is the most beginner-friendly and easiest plugin to quickly improve your WordPress website’s speed and performance! 

Here’s how it works:

It caches your web pages by creating static HTML files and making them readily available for future visits. In addition, it applies browser caching, requesting the browser to save the frequently used but rarely updated files in its local cache memory.

One of the things which makes it the best caching plugin for WordPress is that when you install WP Rocket on your WordPress site and activate it, it automatically applies 80% of web performance best practices right away! 

Furthermore:

WP Rocket can be set to bypass or store dynamic cache depending on query strings and cookies.

Also, it has a system to help refresh the cache in any timeframe requests to help serve a fresh version of the website.

Page caching, browser caching, and GZIP compression are some of the default features that WP Rocket enables for you. But if you don’t settle for the standard settings, WP Rocket also includes advanced features such as:

• Minify CSS and JavaScript files – removes whitespaces and comments to reduce the file size.
• Remove Unused CSS – eliminates render-blocking CSS on your site for faster load time. You can either load CSS asynchronously or remove unused CSS files (the preferred method).
• Load JavaScript deferred – eliminates render-blocking JavaScript to improve load time.
• Delay JavaScript execution – improves performance by delaying loading JavaScript files until the user interacts with the website, i.e., via scroll or click.
• Optimize Google Fonts – combines, preloads, and loads the Google Font file asynchronously (i.e., without render blocking).

With all these features, you can get a blazing-fast website in the blink of an eye, which eventually results in:

Great first impressions, better SEO ranking, & more conversions!

Most importantly, it helps improve the PageSpeed Performance Score and metrics, including the Core Web Vitals grades.

P.S: To set up caching in WP Rocket, go to:

Settings > WP Rocket page > and click on the ‘Cache’ tab. 

WP Rocket already enables page caching by default, but you can tweak additional cache settings from this page. 

Wrapping up

The boost in the performance of your website after implementing caching is simply irresistible. If done right, it can unlock a whole new level of user experience, search engine rankings, and revenue by optimizing your WordPress site for performance. 

However, with so many caching options available, it seems scary to understand which one suits your website well.

But now, as you’re well aware of all the types of caching out there and how they work – it’s time to get cached up! (no pun intended)

The post Server Cache vs. Browser Cache vs. Site Cache: What’s the Difference? appeared first on WP Rocket.

“What’s caching? And what does this mean for my WordPress site?”

As an amateur site owner, you’ve most likely stumbled across the word “cache/caching” or the phrase “use a caching plugin” and found yourself scratching your head over the exact same question.

(Trust us – we know the feeling!)

You see:

One of your primary goals as a website owner is to drive traffic to your site. But if your visitors experience slow page speeds or your website takes more than 4 seconds to load, they will most likely click out without even reading the content. 

And the result? 

Increase in bounce rate and all your hard work going in vain.

Luckily, this is exactly where website caching comes to the rescue! 

Caching is one of the most powerful tools to improve performance, even if you have yet to start using it. 

In simple words, caching can make your WordPress website fast. Like, really fast.

OK, we know what you’re thinking:

If website caching is this powerful, it must surely be a complex technical task to do, right?

Turns out, it’s not as complicated as you may have thought.

In this post, we’ll take a closer look at what caching is, how it works, its benefits, and how you can enable it on your WordPress site – and a lot more!

What is WordPress Caching?

Let’s break down the idea of caching in WordPress this way:

Imagine someone asking you a difficult math problem, like: “What’s 9895357 times 8975?”.

You will look around all confused and won’t be able to answer the question immediately. 

Suddenly, the idea of bringing out a calculator hits you. 

And a few minutes later, after doing the math, you get to know the correct answer and respond back.

Now, if that person asks you the same question again, you will reply at that very minute. That’s because the time-consuming process and hard work had already been done thanks to the calculator. 

And that’s it! That’s caching in a nutshell.

If we apply it to the context of your WordPress website:

1. A user visits your website and makes a request.
2. Your web server takes some time to process.
3. And finally, after a few seconds, it responds to the request by delivering the page.

And it doesn’t stop there.

The server saves a copy of that webpage so that when another visitor makes the same request, it can skip the initial time-taking process and provide the web page much faster.

So, What Does Caching Mean?

If we sum up the whole scenario:

Caching is the storing of frequently used data so it can be accessed faster if someone needs it again. It also prevents the browser from utilizing its resources to load the entire site files again.

It’s simple, isn’t it?

Now before we go any further, let’s discuss the types of caching first.

Types of Caching 

Three of the most common types of caching are:

1. Site Cache (Page Caching)

A site cache, also known as page cache, temporarily stores website data (such as images, webpages, files, and similar multimedia) the first time a web page is loaded. So whenever a user revisits your website, saved elements are quickly retrieved and displayed to them.

However, site caching is a type of client-side caching. This means that all the stored data is controlled by the end user. And as a website owner, your only authority is to specify how long content remains in the cache.

Site caching is perfect for sites with a lot of static content. Because when your website rarely updates, visitors will be able to continue loading your web pages fast while still seeing the latest version of your site. 

On the other hand, it isn’t well-suited for dynamic websites where content frequently updates, such as e-commerce pages with shopping carts.

So, what’s the magic formula?

Consider using a WordPress plugin to take full benefit from site caching. 

There are various caching plugins, like WP Rocket, that you can use to control WordPress site caching. 

WP Rocket is a straightforward caching plugin used to take care of caching across different devices, optimize your files, and improve your website’s performance.

(P.S: We’ll discuss more of the caching plugins in the upcoming sections)

2. Browser Cache

Like site caching, browser caching also happens on the client’s end. 

It works the exact way as site caching but is a cache system built into a web browser. The browser temporarily saves copies of a website’s files, including:

• HTML code
• CSS stylesheets
• JavaScript scripts
• Images

These files are known as “static assets” because they don’t change between visits.

It all boils down to this:

When the user revisits your website, their browser will fetch the cached files and utilize them to assemble your website’s content. And because of this, it doesn’t have to load everything from scratch.

Typically, a web browser will keep its cache for a limited time or until it is full. After that, it will automatically flush out the old content and save the updated one in its place.

However, as a user, you can also manually clear out your browser’s cache whenever you want.

3. Server Cache

Server caching is also similar to site caching, but instead of saving the content on the client’s end, it keeps the content on a site’s server. 

This type of caching is administered on the server without any input from the end user.

For example:

Your server stores HTTP files of your website’s content and serves them immediately when the visitor requests. That way, it doesn’t have to render a new HTTP file every time a user visits the site, reducing the load.

Some of the types of server caching include:

• Object Caching – stores database queries in a server-side cache so that the next time a visitor requests content, the server can deliver it immediately without having to query the database repeatedly.

• Opcode Caching – occurs when the PHP file loads on a web page for the very first time. It stores the results of the PHP script for faster loading instead of executing every single time your website receives a request.

• CDN Caching – A Content Delivery Network (CDN) is a system of servers located worldwide. When a user visits your website, the CDN will serve cached files from the server closet to them in order to reduce loading times.

Why Does Caching Seem To Break Stuff?

– Want to know the scary part?

Caching works flawlessly with web pages having static content (content that doesn’t change unless you change them), such as text, photos, and videos.

But nowadays, websites have a lot of content or features that update automatically or adjust differently for each user looking at the page.

Let us give you some examples:

One example could be an online streaming site. Dynamic entertainment websites (like Netflix) allow their content to be displayed according to a user’s location, watching activity, preferences, and subscription. 

This is an example of dynamic content because content adjusts according to who is looking at the page.

Another example is an e-commerce site.

These websites contain a shopping cart icon on every page, telling customers the total number of items available in their shopping cart. This feature varies for each customer because everyone has a different number of items in their cart. Therefore that number is dynamically generated for each customer.

This type of content needs special care with caching. You need to code things correctly – and if you don’t do that and use a caching plugin, you’ll notice that the website won’t respond as usual (considering the above example: the customer’s cart won’t be able to display the accurate number of items available).

Now, in case you might be wondering:

The main culprit here is PHP!

If the dynamic features present on your website are coded in PHP for output retrieval, they won’t work with caching.

Remember what we discussed at the beginning? Caching stores a copy of your webpage, so the server doesn’t have to load it again when requested. 

Basically, PHP is part of the time taking work that gets neglected when you use caching.

So when you want your website to have dynamic features, you need to use another programming language called JavaScript (JS). JS operates on the browser’s side, so when your page is cached, and PHP is sitting idle, you can rely on JS and AJAX (Asynchronous JavaScript and XML) to handle the dynamic needs of your website.

Can a Caching Plugin Help, and How?

Good news:

The easiest solution for all this is to use a caching plugin on your WordPress site!

A caching plugin is a holy grail for eliminating some of the various steps taken by a browser in generating dynamic web pages. By using a caching plugin, you can achieve various server-side caching benefits (including page caching and object caching). 

Moreover, these plugins also know to offload their cache and renew it whenever a fresh piece of content is published or existing content is updated on your site.

And what’s even better:

With top caching plugins, like WP Rocket, you can also get added performance optimization features that significantly help improve the Lighthouse Performance Score and metrics – including Core Web Vitals – of your WordPress site!

How Caching Works in WordPress

Here’s how caching works:

A cached page will be created for each web page, and when a visitor visits your website, they will be delivered the cached (static) version of each page. 

Within a matter of seconds, WordPress caching plugins minimize the amount of data transmitted between the visitor’s browser, the WordPress database, and the web server, keeping visitors engaged with your site with faster loading times.

How a Caching Plugin Works?

There are many types of caching plugins available for WordPress that make caching a very easy process.

Let’s take WP Rocket as an example:

Using the WP Rocket plugin, you can instantly cache your website by just activating it . In addition, you can enable caching for mobile devices and logged-in WordPress users and specify the time after which the cache will be cleared. 

What’s the catch?

It’s the simplest caching plugin that works straight out of the box and doesn’t require technical knowledge! 

It applies 80% of performance best practices right upon activation – including site (page) cache and cache pre-loading.

All these features make WP Rocket the most beginner-friendly caching plugin to take care of your WordPress caching and make your website blazing fast!

A word of caution: If you’re planning to install more than one caching plugin, thinking it will make your site faster, stop there! Installing more than one plugin won’t make your site any faster. Instead, it’ll make your site slower or even break it. 

Why Is Caching Important for Your WordPress Site?

Whether you want to start today or in the future – you’ll always need caching for your website. 

Here are some of the other benefits of caching for your WordPress site:

1. Makes Your Site Faster 

Speed is crucial for a website. If your site takes too long to load, not only will your website users abandon it, but Google will also penalize it leading to lower rankings. 

That is why one of the primary benefits caching offers is improved site speed!

This results in much faster, easy-to-crawl websites and has a significant impact on your Core Web Vitals grades and the PageSpeed Insights performance score. 

Why is it important? 

Because Core Web Vitals metrics are part of Google’s Page Experience Update – the latest ranking factor launched by Google in 2021. 

Core Web Vitals combined with a better PageSpeed Insights performance score may positively affect your website’s organic visibility and give visitors a hassle-free experience while browsing your page.

2. Improves User Experience 

A fast website = a great UX!

Faster websites are known for reducing bounce rates, as users are not interested in waiting for a website that takes 10 seconds to load. So when the website moves faster for visitors, they will love browsing through it. 

Most importantly, it will put a great first impression on a visitor landing on your website. One glimpse can turn someone into a customer or urge them to move on to another website. So first impressions matter the most when it comes to a website. 

3. Helps Improve Conversions

Faster-loading websites help in higher rankings, and higher rankings mean more traffic!

When you combine it with a good user experience, it will turn all your visitors into actual customers and improve your conversion rate.

4. Reduces Server Load

As caching displays a static copy of the requested webpage, it puts less of a strain on your server and lowers server load by up to 80%. This is especially beneficial when it comes to highly dynamic sites or during traffic spikes.

5. Improves Time to First Byte (TTFB)

Caching is probably one of the easiest ways to lower your Time to First Byte globally. Once your website is cached, resources don’t need to be downloaded every time from the server – leading to reduced server processing time!

How to Enable Cache in WordPress

Here’s how you can manually enable caching on your WordPress site:

Step 1: Open the wp-config.php file, which you will find in the root folder of your website.

If you don’t know where exactly the wp-config.php file is located:

1. Log into your hosting account.
2. Go to cPanel.
3. Click on the ‘File Manager.’
4. Locate the ‘public_html’ folder.

You will find the wp-config.php in this folder.

Step 2: Edit the line that says 

define ('WP_CACHE', false);

And change it to:

define('WP CACHE', true);

Step 3: Create a file named “advanced-cache” and place it within the wp-content directory, just like this:

/wp-content/advanced-cache.php/

How to Enable a WordPress Caching Plugin

Now, if you want to save time by not doing the technical work, then caching plugins offer a quick and easy way to enable caching on your WordPress site!

But unfortunately, most caching plugins come with features that require technical expertise and can easily confuse a user who is not a developer.

However, this is not the case with WP Rocket. 

Installing WP Rocket is the easiest way to enable caching in WordPress. One of the features that makes it the best caching plugin for WordPress is that once you activate it within just a few clicks, you’re already set up and ready to go.

Here’s how you can do it:

• First, you need to install and activate the WP Rocket plugin.

• Once activated, the WP Rocket plugin will automatically turn on the page and browser caching with optimal settings for your site.

• You can see your site’s caching status by visiting the WP Rocket dashboard under the WordPress Settings » WP Rocket page.

Once you land on the Dashboard tab, you’ll get this message:

As for the caching tab, you can find the settings under Settings » WP Rocket » Cache.

In addition to automatically enabling page and browser caching, WP Rocket will activate by default Mobile Cache and Cache lifespan (10 hours). In this tab, you can tweak the settings according to your needs.

Moreover, the plugin includes other crucial features, such as the ones to optimize CSS and JS files, that go beyond caching and make WP Rocket the easiest and most powerful solution to improve your website performance.

Wrapping up

*sigh* – that surely was a hell of a ride.

We hope you find this article helpful!

Website caching is the best way to speed up your WordPress website without sacrificing content or other performance factors. It doesn’t have to be technical or complex. When properly implemented, it will result in much faster load times for your users while decreasing overall server load.

If you’re not caching your WordPress website already, it’s time to get started. You can never go wrong by caching your WordPress site. In fact, it could be one of the biggest ways to your online success.

The post Caching for WordPress: What It Is and How It Works appeared first on WP Rocket.