Speed TestMeasure download, upload, latency and jitter from your browser to the nearest Cloudflare edge; each phase takes up to about 8 s

Download / upload use the 90th percentile of samples over 1MB, similar to speed.cloudflare.com; latency is the median round trip minus server time, jitter is the mean difference between consecutive samples.

The test uses tens of MB of data; with a proxy on it measures the whole "browser → proxy → Cloudflare" path.