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Content Delivery Network (CDN) tests

The SamKnows CDN test measures performance to multiple CDNs by fetching a small object over HTTP. Care is taken to ensure that the same object (or a very similar one) is fetched from each CDN, to provide comparability between the CDNs themselves. Currently an ~80KiB JavaScript library is fetched from each CDN.

Measurements for all tests

  • Average round trip latency for 10 UDP packets (by default).
  • Minimum, maximum, meditation and standard deviations for the latency measurements.
  • The number of sent and received packets.
  • The IP address of the endpoint.

Measuring CDN performance

CDNs are widely used by large websites to distribute static content near to end users. This reduces the burden on the content providers' servers and improves web page load times. CDN operators will place caches inside ISP networks so that traffic does not even need to leave the ISP network. This is beneficial for both the ISPs (it reduces the load on their transit and peering links) and the CDN operators too (it spreads the content serving burden to a wider array of servers).

Available CDN tests

Microsoft Azure

A cloud computing service created by Microsoft for building, testing, deploying, and managing applications and services through Microsoft-managed data centers.


A web infrastructure and website security company that provides content delivery network and DDoS mitigation services. Cloudflare's services sit between a website's visitor and the Cloudflare customer's hosting provider, acting as a reverse proxy for websites.


Apple operates its own CDN network for distributing video, apps, Mac OS X, and iTunes downloads.

Amazon AWS

Amazon Web Services is a subsidiary of Amazon providing on-demand cloud computing platforms and APIs to individuals, companies, and governments, on a metered pay-as-you-go basis.


The company operates a network of servers around the world and rents out capacity on these servers to customers who want their websites to work faster by distributing content from locations near the user.


Google Cloud Platform by Google, is a suite of cloud computing services that runs on the same infrastructure that Google uses internally for its end-user products.