Across the internet you are likely to find a smattering of articles and discussions about why Cloudflare and other such Content Delivery Networks (CDNs) aren’t beneficial for SEO.

The likelihood however, is that those articles are written by people whose services aren’t set up properly, as mentioned by John Mueller — Google’s Webmaster Trends Analyst.

In fact, using a CDN from a provider, such as Cloudflare, can offer a whole host of benefits for companies that want to strengthen their performance in organic search.

Before we look at whether (or why) a CDN can help your website however, let’s take a look at what a CDN actually is.

What is a CDN?

Put simply, a CDN is a group of servers that are distributed across a geographic area. Working together, they help provide the internet to users, and allow for the quick transfer of assets for loading a great variety of content.

The number of sites being passed through CDNs, including the likes of Facebook, Netflix, and Amazon, is growing on a daily basis.

Although it’s easy to confuse them, a CDN is not the same as a web host, as it does not hold content. This means therefore, that you cannot replace site content with a CDN.

Instead, a CDN helps to cache content “on the edge”, which can reduce hosting bandwidth and help prevent interruptions to the service, as well as improve security.

So, let’s take a look at how a CDN can improve your site’s organic search campaign.

How CDNs improve load times

CDNs can help page load time.

The majority of sites use CDNs for one thing — to reduce latency when loading web page content.

Typically, servers are placed at exchange points between different networks, and are the primary locations where internet providers communicate with one another.

Such servers can also be found in geographic areas that experience high levels of traffic.

This means that the physical distance between a user and a website can be drastically reduced; improving load times.

For example, if a person in Leeds was to access a website which is, for some reason, hosted in Madagascar, information must travel over a long distance from website to user.

As you can imagine, this can take a lot of time as each request means that information and assets must travel from the city while passing through a series of routers to get to Madagascar.

This means that latency is increased, and the measurement of a communication between the two locations is often referred to as round trip time (RTT).

If a website is more complex and has more assets, it also means that latency between the two points is increased.

A CDN therefore, that contains a cached copy of the static website between the two points, can shorten the RTT and improve latency.

Caching explained

Caching involves taking static content files from the server of a site and placing them into its network.

Although most CDNs use static versions of sites, there are some CDNs with advanced features which means that dynamic content can also be cached.

Either way, once that information and the assets are present on the CDN, the site can be served to the user from the closest data centre.

Typically, there are four steps involved with caching:

  1. A webpage is requested and is routed to the CDN’s nearest edge server.
  2. A request is made by the edge server from the origin server.
  3. The origin server responds to the request.
  4. The edge server responds to the client.

CDNs also reduce file sizes

Another advantage of using a CDN is the fact that they can actually reduce the overall data transfer amounts between the cache servers and the client, which means that both latency and the required bandwidth are also reduced.

Although it might seem odd that a CDN has the ability to reduce files belonging to a website, this is done through a process called minification.

This works by reducing the size of code; namely the parts that can be read and understood by humans, as computers do not have the same requirements.

When it comes to file compression itself, GZip is a common method of compression and is considered best practice.

Many CDN providers have this enabled as a default, which can reduce file sizes by up to 70% of their original size.

Why load time matters for SEO

Page load time matters for both users and search engines.

Not only does Google state that pages should take less than a second to load, but research has consistently found that pages that take longer than three seconds to load will suffer from higher bounce rates.

The BBC found that it lost 10% of users for every second that it took one of their pages to load.

In fact, Google has long stated that page speed is an important factor in its ranking algorithms, and upgraded its stance on the matter in July 2018:

“Although speed has been used in ranking for some time, that signal was focused on desktop searches.

“Today we’re announcing that starting in July 2018, page speed will be a ranking factor for mobile searches.”

Other studies have found that slower site speeds can affect conversion rates, as faster loading sites tend to convert at higher rates.

Walmart for example, found that by improving page load times by one second, there was a 2% increase in conversions.

You can read more about why page speed matters, as well as how to improve it on your site in this article.

CDNs improve site security

A lock, representing better security offered by CDNs.

In 2019 there are few things more important than site security, and CDNs can defend against man-in-the-middle attacks, data breaches, and DDoS attacks.

What’s more, CDNs can provide proper Transport Layer Security (TLS) encryption, which is a protocol for encrypting data sent over the internet.

Encryption practices are important to prevent people from snooping on data being exchanged between a website and its users.

A TLS protocol provides three components to websites:

  • Authentication
  • Encryption
  • Integrity

To enable TLS, a site must activate an SSL certificate and a corresponding key.

This is necessary as certificates contain files with information about the site, as well as its owner and the public half of an asymmetric key pair.

Browsers and search engines will typically have a list of certificate authorities that they trust.

If for instance, a website contains a certificate that is not approved by a browser, the browser in question might choose to alert users that the site does not adhere to its security expectations.

Furthermore, CDNs provide security to visitors as they connect only to the CDN, which means that a site using an older or less secure certificate between the origin server and the CDN will not affect the user’s experience.

Why security matters for SEO

It goes without saying that security is an incredibly important element of the internet, and search engines take a website’s security measures very seriously when indexing it in their results pages.

Having a site on HTTPs has offered a small ranking boost for some time, and updates to the Chrome browser mean that users will now be warned when a user accesses a site on HTTP.

We’ve covered the ins and outs of HTTPs extensively in this article.

Interestingly, it has been shown that 51% of hacks occur for SEO based reasons, such as hacking a popular site to redirect users to span-specific pages (usually done via database injections of .htaccess redirects).

If Google detects that a site is hacked, you will be alerted in Google Search Console and your site could be subject to a choice of penalties from Google.

If you’re interested in how a website hack can affect your organic search campaign, check out this extensive article by Reza Moaiandin.

Further reading about CDNs by is dedicated to researching the latest technologies in both digital and SEO, and you can read more about how you can use CDNs to improve your SEO on the edge.

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