CDN Performance - Measure with WebPageTest

Customers sometimes ask us how to measure the performance improvement after migrating to KeyCDN. This post is about how to easily and conveniently measure the performance of a website.

CDN performance measured by WebPageTest

The best known website for website performance testing is WebPageTest. It offers performance tests from many locations worldwide with different browsers to choose. Once you have migrated to KeyCDN, WebPageTest will automatically recognize the CDN and display it accordingly. Here's a typical performance test on WebPageTest:

Please note that the very first request to a new POP will be a cache miss (Pull Zone only). If you run performance tests for a new website (e.g. from a development environment), you might be the first one doing a request from another location. If you get a cache miss, please run the test again and you'll normally get a cache hit.

Test results can be public by default. This is useful for others but also if you want to come back a few days later and you can compare previous tests to current tests.

KeyCDN also provides you with an extra HTTP header called "X-Edge-Location" where we provide location information about each POP. The HTTP header "X-Cache" indicates if the content was delivered from the cache (e.g. "HIT from example-hexid.kxcdn.com").

Alternatives to WebPageTest

WebPageTest is not the only tool out there. An alternative is KeyCDN Tools, our own collection of free web tools. Another option is Pingdom Tools. It offers less locations but the test normally executes faster than other online tools. GTmetrix is a good option to get more recommendations how to take concrete action steps on performance. Beside the online tools, there is also the option to use browser features to measure performance from an end user perspective. We prefer Google Chrome for these kinds of testing. See the screenshot below on how to use Google Chrome.

Please bear in mind that a CDN is just one part of the equation. In order to get best website performance, you also need to keep a focus on your website structure and setup. These performance tools will give you important information where to tweak your website.