Content Delivery Network - Worth It?

Are you considering using a Content Delivery Network (CDN) to speed up your website, and wondering if it is worth the cost?

I use a CDN on one of my websites. When I recently had to turn it off to troubleshoot a problem, it seemed to me that my website was still loading pretty fast. That led me to wonder…

Does it really make a big enough difference in the speed of my website to justify the cost?

So I decided to do some speed tests. My results told a story…

What Is A Content Delivery Network?

Just in case you’ve only heard of a “content delivery network” or “CDN” and you don’t really know what it is, here’s the nutshell explanation…

A content delivery network is a network of computers (servers) that is distributed all over the world. All of the static content on your website, like HTML files, images, Javascript files, CSS files, and so on, are spread across that network.

When someone visits your website, your site’s static content is then delivered from the server that is geographically the closest to your visitor. The idea is that it should result in the fastest possible way for your site’s content to arrive at the visitor’s computer.

Content Delivery Network Speed Tests

Here’s some important information about the website that I tested:

The website gets about 500 visitors per day.
Almost 90% of visitors are from the US, and from those, 70% are from Texas.
The website is hosted on a VPS (virtual private server) located in Utah.

I conducted the speed test by selecting 8 web pages with varying content from the website. The testing tool was the excellent web page speed test tool by Pingdom. This tool allows you to run tests from servers in Dallas, New York, and Amsterdam (Netherlands).

My test involved running three tests for each selected web page from each of the three test locations. I did one set of tests with my CDN turned on, and one set with the CDN turned off.

CDN Test Results

I then averaged the test times for each page and each location, with the content delivery network turned on and turned off. Here is a summary of the test results:

Test Location	With CDN	Without CDN	Time Diff	% Time Diff
Dallas	1.77 sec	1.81 sec	0.04 sec	2.21%
New York	1.82 sec	2.00 sec	0.18 sec	9%
Amsterdam	2.41 sec	2.74 sec	0.33 sec	12.04%

CDN Test Observations

From these test results, we see the following:

Web pages are delivered faster when using a Content Delivery Network.
The further away the website visitor is geographically from the web server, the bigger the differences are between CDN delivery times and non-CDN delivery times.
In the case of the website used in these tests, while the percentage time difference between CDN and non-CDN delivery times may seem enough to pay attention to, the actual time differences are only fractions of a second.

Conclusions

So, is the use of a Content Delivery Network worth the cost? Sometimes, but not always!

Ask yourself these questions to decide whether a CDN might be worth the cost to you:

How many daily visitors does your website get? If it is over 1,000 visitors per day, you may want to consider a CDN.
What type of hosting does your website run on? A VPS (vitual private server) can handle more visitors at high speeds than ordinary shared hosting can. If you have shared hosting, your need for a CDN may come much sooner.
How distributed are your visitors across the globe, and how far are they away from your web server? If they are evenly distributed across the whole world, a CDN will help deliver content faster.

In the case of the website I tested, there are fewer than 1,000 visitors per day, the website runs on a VPS, and the bulk of its visitors are concentrated in an area that is only 1,000 miles away from the web server.

As my results show, a CDN is not really worth the cost for my website.

Did you find this helpful? Do you have an opinion on using a CDN? Let me know in the comments…