What is CDN? How CDN Affects Your Website SEO

Content delivery network (CDN) as an important service of cloud hosting, is a system of servers containing copies of data distributed worldwide of the Internet, to deliver the downloadable files like images, videos, scripts, CSS and HTML to global users with extremely fast loading time, in result to boost your search engine ranking and improve the user experience for more visits and better conversion rate significantly.

What is CDN?

what is CDN

The content delivery network is built up of hundreds of CDN nodes grow up in multiple geographic locations over multiple networks foundation. These CDN nodes work with each other to respond to end-users by transparently moving content to optimize content delivery. Optimization includes reducing bandwidth costs, content load time, or improving international visibility of content.

The delivery process is, when there is a request for content, it will be routed to the closest CDN node which has a copy of the content. In the background, there is a mechanism to synchronize content between CDN nodes and the source website. As a result, all global users can pull content from the CDN node nearby with the fastest loading time. Take an example for Yahoo News. Readers from New York visit the CDN node of Yahoo in New York, readers from San Francisco visit the CDN node in San Francisco, and readers from Japan visit the CDN node in Asia. They all read the complete same content by visiting the same news.yahoo.com, but they actually get the content from different Yahoo edge servers.

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How CDN Works

Typically, CDN has two different implementations, Origin Pull and PoP Pull.

Origin Pull:

With Origin Pull, the requested content is pulled from your origin servers as needed and then delivered to your customers. You can set rules for how long your content is cached on the CDN nodes. CDN automatically tracks caching copy and only asks for an update if the cache is expired. This helps reduce the bandwidth and overhead on your web server.

PoP Pull:

With Pop Pull, content is stored persistently on all CDN nodes globally, remaining available edging to international readers at all times. Compared to Origin Pull, Pop Pull needs you to manually update content, although you can manage content at a single place, then they will be synchronized automatically to all CDN nodes.

Origin Pull VS PoP Pull

It’s a tradeoff between these two solutions.

Origin Pull is completely automated, but the cache of content on each CDN node is out of control. There is no opportunity to synchronize the content among CDN nodes. Once the content is cached, it will be refreshed only when it’s expired due to the configured caching time.

PoP Pull resolves the synchronization problem well, but it needs you to upload the content onto CDN manually in addition to more charges on the storage.

Suggested Reading – How to Setup Cloudflare CDN For Your Website

Why use CDN?

There are two significant benefits by using CDN instead of slogging through a single web host, increased conversions, and better SEO.

Increased Conversion

It may be hard to understand how much effect a fast loading website has on the conversation, but several study cases indicate that the effect is obvious. Take Mozilla as an example. After they optimized web page structure as a result of saving 2.2 seconds on loading a page, the download rate was increased by 16%.

In research, 70% of internet readers expect a web page can be loaded in less than 2 seconds. In fact, it’s an unbelievable goal when your website targets global users but it’s hosted at a single place. In this case, it’s highly recommended for you to look for CDN.

Better SEO

Google has introduced that page loading speed is considered a factor in the ranking algorithm. With CDN, the global loading speed can be increased by 30% at least, which helps your website listed higher in Google search results.

How Much CDN Charges?

CDN charges a little money compared to what you can get from it, pricing from $0.07/GB to $0.2/GB. Generally, a content website without video and large images with 1000 pages views daily, costs approximately $5/month only.


If you intend to start a new website, CDN may not be an urgent thing for you, but we recommend you pick a web host by using similar technology. InMotion hosting is highly recommended. They adopt a similar technology named Max Zone Speed to help websites deliver content to end-users in a fast and efficient way, but their Cloud-like web hosting is only pricing at $3.49/mo.

Suggested Reading – A Complete Guideline to Google Search Console

How the Content Delivery Network (CDN) Affects SEO

CDN Affects Your Website SEO

The desperate advertising of the content delivery network misleads many webmasters move to it for faster loading speed and better SEO without full evaluation, but suffered from the drop of Google traffic seriously. seoissue.com is one of the victims. 2 weeks after moved the whole site to Internap CDN resold from Softlayer on Feb 24, the Google organic traffic was dropped by 44.8%.

How Seoissue.com Works With CDN

Seoissue.com used the Origin Pull mode of CDN, created a mirror website complete same as the main website with the subdomain cdn-seoissue.com. Then removed the main domain Seoissue.com from A HOST record and set it as a CNAME record mapping to the Internap domain.

In our expectation and initial analysis, in this case, the requests to the main domain Seoissue.com will be routed to Internap CDN entry, and eventually be routed to pull the content from cdn-Seoissue.com.

This did follow the instruction of using CDN Origin Pull mode in Softlayer as well as the information we found over the Internet. Yes, the website works correctly and successfully delivers content faster than before to global users by leveraging CDN.

How Seoissue.com Suffered

After 2 weeks, we found the Google organic search traffic was dropped by 45%, as well as Google crawled pages daily and page downloading speed in Webmaster.

Well, about revenue, we lost 30%+ daily. We had set the main domain back to our dedicated server and only left static files there such as JavaScript, CSS, and images.

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CDN SEO Impact Analysis

The root causes we analyzed in this disaster can be described from the following 3 aspects.

#1. Google Page Fetch Speed Down from the US

Seoissue.com is an English site designed for US/Canada mainly. Most of the traffic is from these two regions. With CDN, we found the Googlebot Fetch Speed is down from the Webmaster > Diagnostics > Fetch as Googlebot. This prevents the freshness of Seoissue.com to Google and leads the latest articles that could not be indexed immediately. Google search likes fresh content well-known.

Yes, it makes sense for the downloading speed down. As Seoissue.com hosted with a dedicated server in Dallas, the US serving for requests nearby, the response speed is faster than the complicated Content Delivery Network whatever.

#2. Site Targeting

With CDN, Google search cannot recognize the geographic target of Seoissue.com well. It might not be the preferred site for readers from North American from Googlebot’s perspective. Eventually, all keywords rankings were dropped to the United States/Canada region.

#3. Mirror Site Indexed Incorrectly

As mentioned in the former part of this article, we created cdn-Seoissue.com to truly respond to CDN nodes. Unfortunately, the SMART Googlebot indexed many web pages from this domain, although we still didn’t know how the Googlebot got the entry. In this case, CDN-WWW is a complete duplicate to WWW which disobeys the Google Quality Guideline potentially. Seoissue.com was just a CNAME. Eventually, the ranking of WWW in Google search was dropped.

CDN Suggestions :

  • Don’t easily move the main domain to CDN, although that’s the fastest way to get your site onto CDN.
  • When you found the website loading speed is not reasonable, please try to optimize it using Google Page Analyzer instead of moving to CDN without sufficient business consideration and analysis.
  • Put static files like JavaScript, CSS, and Images to CDN only, and modify the reference in your website source code. This may have more works to do, but it’s trust-worth. If you’re using WordPress, Drupal, or Joomla, it takes easily for the change as CDN migration is supported.
  • When you pick a CDN provider, don’t trust the budget one. Akamai is always the best choice, and Internap is a good option although Seoissue.com was suffered from it. These 2 providers have engaged in the field for over 5 years at least. You can easily search a CDN provider from Google, don’t do it for your main site until you have proven by yourself! There are TOO MANY scams and faking introduction about how CDN can benefit your website in SEO.

In this article, we teach you about CDN Network and how it works. CDN is most useful for your website SEO. we try to cover all the information of CDNin this article if you have any question about any topic of CDN and need any type of help about CDN network then comment us in the comment box. if you like this article then share it with your friends. to read more articles about network marketing and SEO, subscribe to our channel via email.

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