Speed Test
Measure your current connection latency, jitter and throughput against a Cloudflare-scale edge. No browser plugins, no tracking.
Measures your connection to the nearest Cloudflare edge. The test transfers real data, so it needs a few seconds and some bandwidth.
About the speed test
Measures your current connection to Cloudflare's edge: idle latency and jitter, download and upload throughput, and latency under load. Runs entirely in your browser with fetch(), no plugin, no app.
A run takes about 20 seconds: a warm-up plus 20 latency probes, then up to ten seconds of downloads with growing file sizes and four parallel streams, then up to eight seconds of uploads with three parallel streams. Throughput is the 90th percentile of steady-state samples, the way Cloudflare's own test reports it, so a slow first second does not drag the result down. During both transfer phases small probes keep measuring latency, which reveals bufferbloat.
Interpreting the numbers
- RTT - time for a tiny request to reach the edge and back. Below 30 ms feels instant; above 100 ms is noticeable for interactive work.
- Jitter - variability of RTT. High jitter hurts VoIP and gaming more than it hurts browsing.
- Download - throughput for a few large parallel transfers. Most home connections peak below the advertised number because of TCP overhead and WiFi.
- Upload - critical for video calls, backup and file sharing. Often much lower than download on asymmetric connections.
- Loaded latency - RTT measured while the download or upload saturates the line. A jump of more than 100 ms over idle latency means bufferbloat: calls and games stutter whenever someone in the household transfers data.