We measure CDN performance 24/7/365 in every part of the world, process the data in real-time and switch CDNs when it makes sense, quickly and automatically, with no effort for you.
After the web page finishes loading, our JavaScript code executes and fetches a small file from a few CDNs, silently in the background. After a test is done, detailed performance data is beaconed to our servers (or a simple 'Fail' if the object did not load completely in 5 seconds).
Our servers receive, validate and store the performance data as it comes in. It then flows into our real-time data processing engine, Analyzr, which constantly calculates a performance score for every CDN per geo (country or country/state) and per geo/ASN, using a carefully crafted algorithm.