Can using a CDN improve your website's ranking?

In an SEO-office hours video, John Mueller, Google’s Search Advocate, responded to a query regarding whether a CDN may enhance ranking.

Page speed, crawling, and SEO was all covered in Mueller’s comprehensive response.

Network for Content Delivery (CDN)

By providing web pages from a server close to the site visitor or anyone attempting to access a web page, a content delivery network (CDN) is a service that offers a global network of servers to speed up the delivery of web pages.

Less “hops” are required for a web page to travel over the Internet to reach a visitor the closer a server is to that visitor.

Therefore, a CDN can dramatically increase the performance of online pages.

Does a CDN Improve Search Results?

Google was questioned about if using a CDN instead of conventional server hosting would improve one’s rating.

The question asked:

“Does putting a website behind a CDN improve ranking?
We get the majority of our traffic from a specific country. We hosted our website on a server located in that country.
Do you suggest putting our entire website behind a CDN to improve page speed for users globally or is that not required in our case?”

CDN And SEO Effect

Mueller answered that a CDN doesn’t have an SEO effect.

Mueller answered:

“So, obviously you can do a lot of these things.
I don’t think it would have a big effect on Google at all with regards to SEO.”

Mueller returns to this point and clarifies it despite his claim that he doesn’t believe it would have a significant impact.

Mueller continued his answer:

“The only effect where I could imagine that something might happen is what users end up seeing.
And, kind of what you mentioned, if the majority of your users are already seeing a very fast website because your server is located there, then you’re kind of doing the right thing.
But of course, if users in other locations are seeing a very slow result, because perhaps the connection to your country is not that great, then that’s something where you might have some opportunities to improve that.
And you could see that as something kind of in terms of an opportunity in the sense that, of course if your website is really slow for other users, then it’s going to be rarer for them to start going to your website more because it’s really annoying to get there.
Whereas if your website is pretty fast for other users, then at least they have an opportunity to see a reasonable fast website, which could be your website.
So from that point of view, if there’s something that you can do to improve things globally for your website, I think that’s a good idea.
I don’t think it’s critical.”

Effect of CDN on crawling

Mueller returned to the subject of SEO and this time talked about crawling and the advantages of a CDN.

Mueller continued his answer:

“It’s not something that matters in terms of SEO in that Google has to see it very quickly as well or anything like that.
But it is something that you can do to kind of grow your website past just your current country.
Maybe one thing I should clarify, if Google’s crawling is really, really slow, then of course that can affect how much we can crawl and index from the website.”
So that could be an aspect to look into.
The majority of websites that I’ve looked at, I haven’t really seen this as a being a problem with regards to any website that isn’t millions and millions of pages large.
So from that point of view, you can double-check how fast Google is crawling in Search Console in the crawl stats.
And if that looks reasonable, even if that’s not super fast, then I wouldn’t really worry about that.”

Heavy crawling by bots, both legitimate and malicious, may be impossible for a slow or underpowered webserver to handle, especially in a shared server environment.

If a shared server encounters that scenario and is unable to serve the requested web pages, it may give up and return with a 500 server response code.

This has happened to me on a shared server when the host advised moving to a virtual or dedicated server environment.

By providing web pages from the CDN instead of the server hosting the actual content, a CDN lessens the consequences of a slow shared server.