CDN Basics

CDN Basics

As the internet continues to develop and users become more impatient, a CDN can keep your website load times down. By using a geographically distributed network of servers, a CDN can reduce latency. As we’ll see, reducing the time it takes for a page on your website to load has a number of benefits, although there are some potential drawbacks too.

What is a CDN?

A Content Delivery (or distribution) Network is a collection of servers placed at key geographical locations. They allow users across the globe to quickly access a cached version of content on your website. Based on a user’s geo-location, they will be served content from the nearest CDN to them. This reduces the amount of time it takes for their web content to load, providing a smoother experience for your website.

Usually, only certain assets are stored on a CDN, including HTML pages, JavaScript files, style-sheets, images, and videos. This static content often doesn’t change, meaning a cached version can be stored across multiple CDN servers. Dynamic content usually isn’t delivered via a CDN due to its constantly changing nature.

Should I Use a CDN?

Content Delivery Networks are used widely, and chances are that a large amount of the online content you consume is served by one. Video streaming services, news sites, and global businesses all employ them. But why is this? Below are some of the main advantages of using a CDN:

  • They’re fast. As we’ve mentioned, load times are important to users. If a site takes more than a few seconds to load, the majority of users will click away. This is not only harmful to your potential sales or interactions; it can also have a negative impact on your search ranking. An important SEO factor is speed. Google’s search algorithm takes it into account when ranking pages. Therefore, a CDN that improves your page load speeds is incredibly useful.
  • They can reduce bandwidth costs. CDNs use caching and optimization to reduce the amount of data that your main (origin) server has to provide. This keeps your bandwidth costs down, which is one of the main costs associated with website hosting.
  • They can improve security. Not only do CDNs reduce the risk posed by hardware failures, their distributed nature means that they can mitigate the threat of Direct Denial of Service attacks and improve the effectiveness of security certificates.

What are the Drawbacks of Using a CDN?

With the many benefits of using a CDN, it seems like they’re useful in almost any situation. However, there are a couple of drawbacks:

  • Security issues.  Public content delivery networks aren’t necessarily all that secure from interference, particularly of remote hosted JavaScript.
  • Reliability concerns.  If the CDN network goes down, you have no control over when it comes back up, although this is very rare. 
  • IP Restrictions. Some countries or areas ban the IPs used by CDN services. This means some elements of your website may not load in particular locales.

Despite these two drawbacks, CDNs are an incredibly useful way of speeding up page load times for customers across a variety of geographical locations.

Ready to get started?