Can we determine if the site is on a CDN?

Question

Is there a way to determine if a site is in a content delivery network, and if so, can we tell which service they use?

Answer 1

Just take a look at the URLs of the images (and other media) of the site. Reverse lookup the IP hostnames that you see there and you will see who owns them.

Answer 2

The method accessible from the command line is used by the host command, and the -a flag should see a DNS record, for example.

host -a www.visitbritain.com 

Return:

 www.visitbritain.com. 0 IN CNAME d18sjq5nyxcof4.cloudfront.net. 

Here you can see that the CNAME record tells us that the site uses the cloud interface as a CDN.

Answer 3

I built this little CDN identification tool used by a website or domain, feel free to try it.

URL: http://www.whatsmycdn.com/

Answer 4

You can also specify from the HTTP media headers if the URL does not provide it. For example, media served by SimpleCDN have Server: SimpleCDN 5.6a4 in their headers.

Answer 5

Cdn planet now has a search tool cdn on github http://www.cdnplanet.com/blog/better-cdn-finder/ tool set on the command line and allows you to transmit the host names and check whether they are using CDN.