Speed Test by Cloudflare

speed.cloudflare.com is a tool that allows you to measure the speed and consistency of your connection to the Internet. You can use it to verify that the speed your ISP promised you is the speed you are getting, compare different ISPs or test network connectivity in different parts of your house.

The measurements run on the Cloudflare network, which spans data centers in over 180 cities worldwide. This ensures you are testing against a server that is close to you, which means you are measuring only the speed of your ISP, with minimal networks in between that may impact your score.

Why build another speed test tool? There are many speed test tools out there. Our mission is to help build a better Internet. To do so, we believe in giving users a choice of different services: you shouldn’t be tied to one provider and you should be able to compare results across different tools.

How does it work? The test uses the Cloudflare anycast network to test network speed and latency. By leveraging the anycast network, the closest data center is found by network routing based off of BGP. This is a more accurate way of finding the closest data center than traditional methods, such as geo-location based off of your IP address.

Speed is measured by downloading/uploading progressively larger files and taking the 90th percentile speed. Latency is calculated by measuring the time it takes before your browser actually starts receiving data on a request, also commonly referred to in browsers as time to first byte. Jitter represents how stable your latency is: how big of a difference do we see between latency measurements? It's calculated as the average latency delta between any two consecutive measurements.