4 Reasons CDNs Are Crucial for SEO


As we’ve mentioned in our glossary, a CDN is a geographically distributed network of servers that deliver content to a user based on their location.

This may sound technical, but it’s rather straightforward — a standard website tends to live on a single server which is physically located somewhere in the world. When we visit that site, we are accessing information located on that server.

A CDN, however, leverages other servers around the world to allow users to access the same website but to do so on a server that’s much closer to them, saving the server and the user both time and resources.

CDNs have been around since the late nineties and only gained mainstream attention in the last few years — but the question remains — what benefits can a CDN provide with regard to SEO? And do we really need to invest in one?

Let’s find out!

1. Faster Page Speed

Undoubtedly, the most notable difference we can experience with a CDN is speed.

You may not have even realized it, but a website that is hosted on the other side of the world may take longer to load for you, but thanks to a CDN, you will experience much faster loading times because a copy of the site was distributed to a server much closer to you.

Search engines have confirmed page speed is a factor they take into consideration for their algorithms (which organize the SERPs), therefore it should only be logical for us to implement every measure we possibly can to ensure our website loads as fast as possible.

47% of consumers expect a web page to load in 2 seconds or less. With that in mind, enabling a CDN is optimal not only for visibility purposes, but for the goal which SEO facilitates: conversions.

2. Lower Bounce Rate

Faster page loading times contributes to a greater user experience. But that’s not all.

According to the most recent data available, over 40% of website visitors abandon a website that takes more than 3 seconds to load. And perhaps the most alarming statistic of all: Every second delay in page response results in a 7% reduction in conversions.

Search engines notice when users “bounce” back to the search results from a landing page and will factor it into their algorithm, promoting websites that have a lower bounce rate over those who have a higher one.

In speeding up your site, CDNs also effectively drive down bounce rate which helps both the user experience and subsequent rankings.

3. Enhanced Security

Website security has become increasingly important to search engines in recent times. After they publicly confirmed secure protocols as a ranking factor, the internet saw a shift toward security and encryption. In fact, as of 2019, over 95% of all search engine results are HTTPS (sites that utilize SSL to encrypt data transferred between a website and web browser).

While CDNs can provide HTTPS for your site, it doesn’t stop there. CDNs can also protect websites from hacking and DDoS (distributed denial-of-service) attacks.

A denial of service attack happens when a large number of bots make requests of your server in order to overload it and subsequently bring down the site. The distributed nature of a DDoS attack makes it practically impossible to mitigate using traditional techniques, since the attack originates from so many diverse sources that conventional blocking mechanisms such as firewalls and deny rules are rendered useless.

Not only can a CDN distribute these requests evenly over all of its servers and prevent your site from going down, it can also temporarily blacklist IP ranges and block geographic regions issuing the requests, not to mention the historical data CDNs have on DDoS and botnets which allows them to proactively circumvent such attacks — something your host cannot do on its own.

4. 100% Uptime

Some websites experience a sudden influx of visitors due to a viral video, link campaign or other form of successful promotion. When that happens, servers tend to crash due to the rigid nature of hosting tiers and pricing plans which can’t handle the extra bandwidth requirements.

A CDN can effectively mitigate such crashes from happening due to the nature of their load balancing capabilities, dividing the load time up among various servers and keeping your site online and as fast as ever.

Large spikes of traffic or hardware failures can interrupt normal website function. CDNs, however, can handle more traffic and withstand hardware failure better a single server can by its very infrastructure.

Search engines don’t like to display websites that are experiencing downtime. You could be temporarily removed from SERPs, not to mention how many lost conversions you could suffer from a site that’s down.

Final (Important) Thought

Any of the aforementioned reasons would be sufficient to warrant the case for a CDN. If you take optimization of both search visibility and conversions seriously, there is no excuse to not invest in a content delivery network that works.

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Sebastian Hovv is a SEO consultant, blogger, speaker and author of the book, The Little White Book of SEO. With over 13 years of experience in SEO, he has become an expert in the field and a contributor to the world of digital marketing.