What is a Content Delivery Network? The Ultimate WordPress CDN Guide

A WordPress CDN provides an easy way for you to improve the performance and stability of your site as a whole, especially to international users. The term "CDN" is likely one you've heard once or twice during your time as a site owner, but what is it exactly? That's what we're going to explore in this post.

We're going to take a deep dive into this topic and how it relates to WordPress. We'll go over the advantages and disadvantages that come with using a CDN and briefly cover a few services you can use.

Let's start with a more technical description.

What is a Content Delivery Network?

A content delivery network, more commonly known as a CDN, is a system of connected web servers distributed across multiple locations, typically around the globe. It's used to distribute pages, images and other content to users based on where they're located.

But how does it work? The server your site is installed on is called your "origin server." Without a CDN, this server sends content to all of your users regardless of where they live. If your origin server is in New York City and your user lives in the United Kingdom, your content will be served from your origin server despite the fact that your user lives an ocean away.

When your site is connected to a CDN, your content, typically JavaScript (JS), Cascading Style Sheets (CSS) and images, is stored and delivered from multiple servers around the globe. So, instead of that user from the UK receiving your content from your NYC origin server, they'll receive it from a server in Europe that's closer to where they live.

What is a WordPress CDN?

A WordPress CDN is simply a CDN provider that integrates with the WordPress content management system seamlessly. They do this via a plugin, a direct integration with particular web hosts or both.

The integration ensures the performance benefits a CDN provides are optimized for the platform you used to build your website. It also makes it easier for you to install and manage a CDN.

Advantages of Using a WordPress CDN

Most websites use CDN's for the increased performance they bring and the subsequent benefits that follow, and it's certainly true. When the British user from the above example is able to receive content from your website from London rather than NYC, they're able to receive it at much faster speeds.

This is just one advantage of using a CDN. Here's a full glimpse of the advantages we'll be covering:

• Better Performance
• DDoS Protection
• Lower Bounce Rate
• Better for SEO
• Storage for Large Files

Better Performance

When you distribute your content through a content delivery network, you distribute your site's traffic to servers located all around the world. The result is faster page loading times for all users because they aren't all accessing your site's heaviest bits and pieces from the same source.

Think of it as a city street in comparison to a highway. A city street typically has one or two lanes of traffic while a highway may have as many as four. If 100 cars are travelling down each road, they'll move much faster when they're distributed among the four lanes of the highway.

This is how a CDN improves your WordPress site's performance. The city street is your origin server, the highway lanes are the global servers your CDN offers and the cars represent your site's users.

This load balancing also makes your site more stable, especially when it receives surges in traffic. The auto-scaling from cloud servers provided by hosts like Kinsta can prevent your server from crashing during such events, but you can truly relieve some of the pressure your server experiences while avoiding overage fees by distributing your traffic among a CDN provider's network.

DDoS Protection

When you connect your site to a CDN and distribute your traffic among servers located across the world, you also enable DDoS protection for your site. DDoS, or distributed denial of service, is a type of cyber attack in which the attacker floods a site's server with an unprecedented amount of traffic, causing it to crash and return 503 errors.

Having your site distributed among as many servers as possible makes it highly unlikely for these types of attacks to make your site unavailable for all users. Plus, many CDN providers and quality hosts offer web-application firewalls (WAF's) for even more protection against these types of attacks.

Lower Bounce Rate

Internet users abandon sites they feel take too long to load, which is more than a few seconds for most. Faster page speeds allows your site to load faster overall for every individual user. This, along with the aforementioned DDoS protection, can increase the number of users who choose to stay as soon as they visit your site, lowering your bounce rate.

Better for SEO

If you're not yet aware, site speed is an important ranking factor in Google's algorithm. Bounce rate counts as well, though it's certainly less important than page loading times. Both of these metrics help Google determine the usability of your site.

User-friendly sites rank better in Google as the search engine dedicates the first page of each result to valuable pieces of content published by the web's best-performing sites. Faster speeds and a lower bounce rate demonstrate your site's usability.

Storage for Large Files

Many CDN services offer CDN storage for your content, particularly high-quality images and videos. It allows you to offload some of the pressure your server endures by storing large files on its own. When you serve and store these files with your CDN, your users will experience faster speeds no matter how large your files are. It can even help you obtain smooth video streaming.

Disadvantages of Using a WordPress CDN

As many benefits as a WordPress CDN can provide for your site and as great as those benefits can be, there are still quite a few reasons as to why a CDN may not be suitable for your business at this time.

Some disadvantages don't provide a reason for you not to use a CDN. They simply demonstrate a need for you to choose a WordPress CDN provider wisely.

These are disadvantages we'll be going over:

• Cost
• Another Area of Tech for You to Learn
• Risks
• Location of Servers
• Support Availability

Cost

CDN services can be quite expensive, and their cost can be unpredictable. This is because most CDN providers don't offer fixed monthly or annual rates you're used to paying for web services.

Source: Unsplash

Instead, you'll pay for the files you distribute and bandwidth you consume every month. An example, pulled from KeyCDN's pricing page, is $0.04/GB for the first 10TB you distribute every month to users in North America.

You can see how difficult it can be to predict how much you'll spend on this type of service on a month-to-month basis.

Another Area of Tech for You to Learn

Setting up, managing and using a CDN can be a daunting task for a blogger or novice internet user. Fortunately, a WordPress CDN provider can provide seamless integration with your site or even a plugin you can use to perform important tasks from the WordPress dashboard.

Still, it's never as easy as "set and forget." You're going to need articles like this to help you understand what a CDN is, if you need one, which service to use and how to set one up. Even managing a CDN can be intimidating for novice users, even if the UI is intuitive.

Risks

While budget is most certainly an important factor to consider, it's to choose a reputable service with a lot of experience in the business regardless of how much they cost. New services come with a lot of risk factors in regards to longevity.

They may start running low on money and pass the responsibility over to customers by raising prices. They may go out of business, forcing you to take your files and find a new network to store and distribute them with.

They may also, and this one applies to new and old services alike, offer low-quality services. Maybe your distributed content returns a lot of 503 errors and broken images. Maybe support isn't very helpful when you have questions or technical issues.

All of this must be considered before you choose to integrate your site's content into a CDN provider's network.

Location of Servers

This is another factor that won't help you decide if a CDN is right for your business. It's simply another example of why you need to choose a service carefully.

All content delivery networks are different. Some only have a small handful of servers while others have hundreds. Some have servers located on every continent on Earth while others only cater to two or three.

Use your site's analytics to determine where the majority of your content is sent from and if the users in that region are of value to you. The CDN service you decide to go with should have servers located nearest them to the regions you'd like to serve.

Support Availability

This one ties into the section about learning new tech. If you're new to CDN services, you'll likely have a lot of questions. Plus, if you ever experience problems with your site or with the service's ability to deliver your content, you'll want to speak with a support team member.

If you choose a service with small windows of time you have to contact support, you may experience a lot of downtime if you have questions or experience issues with the delivery of your content.

Choosing a host with longer support hours ensures you're never left in the dark when issues occur.

What to Look for in WordPress CDN Providers

Because the fallout of using an unreliable CDN service can be quite catastrophic, it's important that you know what to look for and that you take your time to consider your options.

Let's break this section down into the various terms you'll find on a typical CDN provider's Features page:

• Data Centers
• Cost
• Performance
• Security
• Storage
• Ease of Use

Data Centers

Data centers are the location-based servers CDN providers have in their networks. They represent where in the world the service can deliver your content at fast speeds. It's important that you don't simply pick the service that offers the highest number of data centers for this reason.

Instead, choose a CDN provider that has data centers in locations you receive the most amount of traffic from. If most of your traffic comes from the United States and various European countries, for instance, choose a CDN provider that offers multiple data centers in those regions.

Cost

It's important that you don't simply choose the CDN provider with the lowest prices or even the one with the highest prices because you feel that's the best way to achieve the performance and quality of service you're looking for.

Cost is important. The amount you'll be spending on this type of service on a month-to-month basis is an obvious reason to consider it carefully. However, it shouldn't be the most important factor in your decision.

Instead, consider the other features in this section to determine which features aside from cost are important to your business specifically. Consider cost only when you've used these features to narrow your options down to two or three choices.

Performance

It's best to look at reviews of the individual CDN providers you're interested in to get a sense of their real-world potential for performance. This mainly means discovering how much a site's page speed improved after implementing a CDN. If you can find additional metrics, such as how much a site's bounce rate improved, you'll have even more evidence of what particular CDN's can do for your site.

Apart from that, there are a few features or terms you'll find CDN providers claim they offer. Here are quick explanations of two:

• Intelligent Routing - Detects congestion in the normal route the traffic your site receives as well as the routes the service's overall network uses, then re-routes it to faster paths.
• Instant Cache Purging - This is something you can initiate yourself with most CDN's. It allows you to remove outdated or unused cached files that pass through the network. Many CDN's allow you to choose which files to purge. Your choices are typically an individual URL or tag or your entire site.

Security

CDN's are a form of security by nature. Distributing your content across multiple servers around the world is a simple way to provide DDoS protection. Other forms of security these types of services offer include WAF's, bot deterrence, a blacklist for malicious IP addresses and SSL certificates for URL's generated by its network.

Storage

Not all CDN providers offer storage, so if you have large files you'd like to display on your site, be sure to limit your options to those who do. Storing such files on your CDN's servers moves pressure away from your origin server and improves site speed that much more. Plus, it can result in smooth video streaming if these are the types of files you'd like to store.

Unfortunately, not all CDN providers include storage in their base plans. It's typically an add-on service. For example, KeyCDN's pricing starts at $0.01/GB per month when you use over 150TB, but its CDN storage service costs an additional $0.01/GB.

Ease of Use

Your research of each CDN provider you're interested in should lead to screenshots, reviews and tutorials that demonstrate the service's dashboard and how easy it is to use. Be sure to choose or break your options down to providers that make sense for your skill level. If a service receives countless positive reviews but seems too technical, it's probably not the best option for you.

CDN Providers We Recommend for WordPress

There are a number of different quality CDN providers you can use, but we've narrowed it down to a list of five with three listed below. You can learn more about each of these services as well as a couple of additional services in our post on the best CDN providers available for WordPress.

• BunnyCDN - BunnyCDN is an affordable CDN provider that offers a network of over 35 data centers, numerous security and performance features, and storage. You can get started with this CDN with a 14-day free trial. Also you can learn more about this service in our BunnyCDN Review.
• KeyCDN - KeyCDN is a CDN provider that focuses its service on Europe, though its network of over 30 data centers provides numerous servers in other continents as well. Like BunnyCDN, it also offers security, performance features and storage for large files. A 14-day free trial is available as well. The CDN is also integrated seamlessly into Kinsta's hosting platform if you want quality cloud hosting and a simple way to implement a CDN for your site.
• Cloudflare - Cloudflare is one of the most well-known CDN services available in the web hosting industry, and not just among the WordPress community, either. It has a huge network with over 200 data centers, sophisticated security and performance features, and a video hosting service. Many hosts have this CDN integrated into their control panels, including such hosts as SiteGround, Bluehost and DreamHost. You can get started with this CDN for free with or without a direct host integration.

Final Thoughts

While affordable solutions like BunnyCDN do exist, WordPress CDN's are still an extra service you're required to pay on a monthly basis if you choose to implement this technology on your site. This is why you may not want to use it until you truly need it.

Every site owner should connect their WordPress site to a content delivery network at some point down the line. It'll provide performance boosts beneficial for users and search engines alike. You'll also have site stability and DDoS protection as your traffic is distributed among multiple servers around the world.

However, CDN's are really only useful for three reasons when it comes down to it: distributing large files, serving a large amount of users and serving users in different regions. If you have a high-traffic site but only serve users in one region, you should still consider using a CDN. You'll just need to make sure the provider you choose offers multiple data centers in the region you serve.

If you don't use large images or videos, the simplest way to determine if you need a CDN is to discover which regions the majority of your traffic comes from, then use a tool like Pingdom to test your site's speed from Pingdom's regional test locations. If your site takes longer than two to three seconds to load, you should consider using a CDN, then ensure you're optimizing your site in every other possible way.

As for how to integrate your WordPress site with a CDN provider, check the CDN provider's knowledge base for a WordPress tutorial if your host doesn't allow you to enable one from its dashboard.