A common misconception is that Content Delivery Networks (CDNs) can harm a website’s organic rankings. While popular, this idea was never proven to be true.
In fact, Google representatives have repeatedly stated that using CDN URLs is fine.
They’ve also dispelled the myth that you can get a big SEO boost if you host images on the same host/domain as your website (cdn.yourwebsite.com) instead of on a separate site/subdomain (yoursite.cdnprovider.com).
Using the same domain simply means you won’t need to redirect if you ever change CDNs.
Also, potential CDN-related ranking problems can easily be avoided by adding a canonical header. This header tells Google that the CDN content is a copy and points the search engine to the original.
Some CDN providers let you add this header manually, but with NitroPack, it's added automatically for all resources. All assets hosted on our CDN have a canonical link header pointing to the original resource by default.
From what Google has said so far, we can only determine that using a CDN doesn’t affect SEO. There’s also no large-scale research showing that CDNs have harmful effects on organic rankings.
Web.dev’s team also advises using a CDN in multiple articles and videos. Being a Google property, it doesn’t make sense for them to give information that directly contradicts SEO best practices.
Even if we completely disregard all of Google’s statements, there’s still one crucial argument for CDNs:
They have been incredibly popular for years. The largest websites in the world use Cloudflare, CloudFront, Rackspace, Akamai and other CDNs daily. If these services harmed organic rankings, it’s improbable that they would’ve ever become so widely used.
That said, one other myth around CDNs still persists, despite being debunked over 15 years ago - the unique IP problem.
According to this theory, it's crucial to have a dedicated IP only for your domain. This creates an issue, as using a CDN sometimes means sharing the IP with other sites.
Sharing the IP makes your site vulnerable because other sites with the same IP might be doing some shady stuff. Once Google finds out about it, they penalize the site and, for some reason - the IP.
From that point on, the entire IP is compromised and all domains on it get a ranking penalty.
This idea is wrong for a few reasons and Google representatives have said so many times.
Back in 2006, Matt Cutts (former head of Google’s web spam team and distinguished engineer at the company) said the following:
“Google handles virtually hosted domains and their links just the same as domains on unique IP addresses”.
If you’re interested, check out this article for his full statement.
Ten years later, John Mueller also had to weigh in during a Webmaster Central episode when asked the following question:
“All of our group websites are on the same block of IP addresses. Is that a problem?”
His answer:
“No. That’s perfectly fine. That’s not something where you artificially need to buy IP address blocks...Especially if you’re on a CDN, then maybe you’ll end up on an IP address block that’s used by other companies as well...That’s not something that you need to artificially move around.”
In other words, even if your CDN changes your site’s IP address with one of theirs (which isn’t always the case), you have nothing to worry about from an SEO standpoint.
For the full video, click here. You can find John Mueller's answer around the 24-minute mark.
Also, Google’s Official Webmaster Guidelines never mention unique IPs as a good practice. If IPs were that important, there would’ve been at least a few sentences dedicated to them.
Put simply:
It makes no sense for Google to penalize all domains behind the same IP.
This would make its system incredibly easy to manipulate. One person with a malicious website could ruin the whole IP for thousands of legit sites.
With CDNs and shared hosting plans being so popular, it’s impossible for Google not to have a mechanism for distinguishing between different domains on the same IP.
Finally, using a CDN doesn’t necessarily mean your site’s IP address will be changed.
With some CDNs, the IP address and the DNS records associated with the domain aren’t changed and the initial HTML is served from the origin server. In these cases, only static resources (images, fonts, CSS, JS) are serverved from the CDN.
Google doesn’t care where these resources come from. The important thing is that they’re served through HTTPS, which all reputable CDN providers use.
To summarize:
Using a CDN doesn’t hurt your SEO. Google representatives have confirmed that multiple times;
Hosting images on the same host/domain as your website as opposed to on a separate site or subdomain doesn’t give you an SEO boost;
The only thing you should worry about is adding canonical headers to CDN resources. Any good CDN provider will let you do that easily or do it for you;
Having a unique IP is irrelevant to Google. They treat unique IP addresses just the same as shared ones.