HTTP throughput diagnostics via Cloudflare edge | no tracking, no ads, results stay in your browser
backend: probing…
$ idle — press start
Metric
Result
Ping (min RTT)
—
Jitter (mean |Δ|)
—
Download
—
Upload
—
Bufferbloat (ping under load)
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> methodology
Ping / jitter: 2 warm-up requests are discarded, then 10 timed requests to /ping on your nearest Cloudflare edge location. Ping = fastest sample; jitter = mean absolute difference of consecutive samples. This is HTTP RTT over TLS, not ICMP — expect slightly higher numbers than a terminal ping.
Download: 8 parallel chunked streams for 10 s from /down; the first 1.5 s (TCP/TLS ramp-up) is discarded before the result is computed.
Upload: 4 parallel ~8 MiB POSTs for 10 s to /up.
Bufferbloat: pings fired while the download saturates the link; the median increase over idle ping is graded A–F (A ≤ 5 ms, B ≤ 30 ms, C ≤ 60 ms, D ≤ 200 ms, F above).
Suitability badges: 4K streaming ≥ 25 Mbps, video calls ≥ 5/3 Mbps at ≤ 100 ms, gaming ≤ 50 ms ping and ≤ 10 ms jitter.
Honesty clause: this measures HTTP throughput between your browser and Cloudflare's edge — not your ISP's rated line speed. Bottlenecks on your side (Wi-Fi, VPN, device) are included in the result.
The last result is exposed as window.speedtest — poke it from devtools. And as usual: help() works, too.
