ISTB · Internet Speed Telemetry

Download over time

Cloudflare full test, split by file size. The shaded band spans the slowest-to-fastest of the three sizes each cycle. Tick a source below to overlay its 25 MB download for comparison.

Cloudflare sizes:

Upload over time

Cloudflare full test, split by file size with the same spread band. CDN sources measure download only, so there's nothing to overlay here.

Cloudflare sizes:

Speed trends

Pick a test and metric. File-size split shows whether short bursts beat sustained transfers — a classic throttling tell.

Latency & Bufferbloat

Unloaded vs loaded latency. When loaded sits well above unloaded, your connection chokes under load — that's bufferbloat, and it's what makes calls stutter while something downloads.

Jitter over time

Variation in latency between samples. Low and flat is good; spikes mean an unstable line that hurts real-time apps.

Download by source

Same line, different servers. If one source is slow while others are fast, the bottleneck is that route — not your connection. Cloudflare uses the full-test download.

Performance by hour of day

Average download for each hour, pooled across all days. A dip during evening peak hours is the signature of congestion or throttling at busy times.

Test reliability over time

Share of tests that failed, by day. Bursts of errors often line up with outages or line faults worth raising with your ISP.

Broadband performance report · generated locally

Performance summary

Enter your advertised speeds above to generate a plain-language summary.

— Measured by ISTB · Cloudflare full test · times in local zone

This summary is generated entirely on your device from the file you loaded. It isn't legal advice, but it gives a non-technical, factual snapshot of sustained performance you can share with your provider or a regulator.

Drop your results file to read it