impact of cdn on crawling

Impact of CDNs on Crawling and SEO Rankings

Let’s understand what CDN (Content Delivery Network) is in actuality with a very basic and simple explanation. Suppose you are visiting a website, and you see a lot of images, videos, or other content, and what you are experiencing is the loading time is too much, which can simply make you feel irritated, right? You know the Impact of CDNs on SEO and why it is happening. The reason behind that is maybe you are living on the other side of the world and the content you were searching for is far from you and taking time to reach you. This is where the CDN comes in to solve the problem.

What is a CDN?

A Content Delivery Network, therefore, is a group of servers located strategically around geographically distributed various locations worldwide with the main agenda of making it possible for information to be delivered promptly as per user geolocation, thereby serving the client using the closest available server assigned to him. CDN effect on crawling is mainly about what the CDNs do is accelerate the total performance of a website by creating cached copies of content within the website, like its feature images and videos, amongst others.

 

You know that the concept of CDNs started with the emergence of the World Wide Web in the early 1990s and in the late 1990s, Akamai Technologies founded the first generation of CDNs that brought this technology to a commercial level. And with time, it continues to change and update as people increasingly get more dependent on online platforms. 

What Are CDN Benefits?

  • Boost Speed: By serving content from nearby locations, they speed up load times for users.
  • Reliability: If one server goes down, others can still serve the content, keeping the website up.
  • Global Reach: Websites can have better performance for users anywhere in the world.
  • SEO: Faster websites are favoured by search engines, helping improve rankings.
  • Security: CDNs help protect websites from attacks like DDoS (Distributed Denial of Service), which overloads servers with traffic.

How does CDN Work?

  • Global Network of Servers: A CDN has multiple servers located in different countries or cities. These servers are called edge servers.
  • Caching Content: When you visit a website for the first time, the CDN will store (or cache) copies of the website's content on these edge servers.
  • Serving Content: The next time someone from your area visits the same website, the content is served from the nearest edge server. This cuts down the time it would normally take to retrieve that content from a distant server.

Let’s understand the process of how CDN and SEO work with an example for more clarity. Think, you visit a restaurant that deals in fast food only and it has only one centre kitchen, which is quite far away. Then it is normal that it would take time to get to you. But if the restaurant had many kitchen centres or every restaurant had its own, then your food would be ready and you would get served faster, Right? That is how CDN works! They make sure website content is delivered to the user from the nearest or closest location to provide a better user experience to consumers. 

How CDNs Help Google Crawl More Efficiently:

One of the major benefits of using a CDN is that it helps Googlebot crawl your website more quickly and effectively. Also improves your site’s SEO and CDN performance. Googlebot is a tool of Google that it uses to crawl and then index your site pages, helping to determine search rankings. Here’s how CDNs help:

 

Faster Crawl Rate: When Googlebot finds a CDN, it knows that the website’s content will take the least time to load and will be delivered faster. As a result, it allows Googlebot to crawl more pages in a shorter period. A CDN speeds up this process, providing your website content with more chances to be indexed, which can improve your overall SEO too.

 

Optimized Crawl Budget: Googlebot has a limited crawl budget, which within a certain time frame visits your websites and crawls the number of pages of your site according to it. But with CDN it allows Google crawlers to visit more pages in a limited amount of time, making the most of your crawl budget.

 

However, consider that when you first implement a CDN, the cache isn’t preloaded. It means that when a Googlebot visits your page for the very first time, it content must need to be served from your origin server. This initial fetch could consume some of your crawl budget, but once The CDN cache is ready and warmed up, the further crawling becomes more efficient and even faster. 

What are the Potential Causes of CDNs and Crawling:

Although CDNs are usually known for improving website performance, there are times when they can completely block crawling. Google classifies these issues into two types

 

There’s no doubt that the CDN is a huge benefit from the perspective of better SEO and crawling for your site. But there are always two sides to everything, and the same thing applies here. With plenty of advantages of CDNs, it also comes with some disadvantages. It sometimes creates crawling issues if they are not set up correctly; here we have listed some related issues of it.

 

Well, according to Google, the issues are being classified into two types:

 

1. Hard Blocks

A hard block occurs when a CDN returns an error response, such as a 500 (internal server error) or 502 (bad gateway). These errors let Googlebot know that something's wrong with the server, slowing down its crawl rate. In extreme cases, Google might remove affected pages from the search index.

 

What to Do: Always ensure your CDN returns a 503 (service unavailable) for temporary issues, not a 500 or 502 error. A 503 tells Googlebot that the site is temporarily down and that the content will be available soon.

2. Soft Blocks

A soft block occurs when your CDN shows a "Are you human?" CAPTCHA or pop-up to Googlebot, which blocks the crawler from accessing your site. If this happens, Googlebot may not be able to crawl your pages, leading to indexing issues.

 

How to solve: If your CDN already shows popups and CAPTCHA to Googlebot, then ensure it sends a 503 status code in such verification attempts. A 503 status code lets Googlebot know that the content is temporarily unavailable.

How to Solve CDN-Related Problems:

Use Google’s URL Inspection Tool

The URL Inspection Tool in Google Search Console allows you to identify how Googlebot detects your pages. This can assist you in determining if your CDN is showing any error pages or blocking Googlebot.

Check for Blocked IPs

Sometimes, a CDN’s firewall (known as a Web Application Firewall, or WAF) may block Googlebot’s IP addresses. You can compare the IP addresses to Google’s list of authorized IPs to check if any are being blocked.

Debug CDN Settings

Ensure everything is set up correctly by checking it up with the CDN provider in case you ever notice any errors in it. By keeping an eye on your CDN logs, you can fix errors like 500 and 502.

Conclusion:

In this blog, we have seen how to improve SEO with CDNs. CDN can positively impact your crawling speed and boost your SEO ranking when implemented correctly. However, if not configured properly, it might cause crawling problems such as hard blocks, soft blocks, ranking drops, and even misconfigured caching. By identifying the whole CDN process and possible issues, and by implementing it strategically, you can ensure your website pages stay indexed and allow your business to rank on top of search engine result pages with maintained SEO efforts.