Who runs this site
SpeedTestAgent is an independent speed-test site, not an internet provider. We explain what each measurement can — and cannot — show, so a single result is treated as a useful reference rather than a definitive diagnosis.
Editorially, our guides explain when figures are estimates, list their sources, and welcome corrections via the contact page. The site is funded by advertising and occasional commercial referral links, never by selling test data. Partnership inquiries are also welcome via the contact page.
What it measures
SpeedTestAgent measures download and upload throughput, HTTP latency, jitter, and the increase in HTTP latency under load when enough samples are available. It does not measure IP packet loss. Each transfer phase uses a 2-second warmup followed by an 8-second measurement window. Headline throughput is downloaded bytes received or uploaded bytes acknowledged by the server, divided by the elapsed wall time in that window; it is not a percentile of short samples.
How it works
After a short link probe, the browser uses four parallel download workers and six upload workers. Request sizes adapt to observed request timing, subject to 250 MB download and 50 MB upload request caps. Throughput counts received download bytes or server-acknowledged upload bytes during the measurement window; see the methodology page for timing and limitations.
We prefer Cloudflare endpoints when their probes succeed. Download and upload choose their backends independently, so either direction can fall back to our own backend if Cloudflare is unreachable (for example, because a corporate firewall or browser extension blocks speed.cloudflare.com). The selected endpoint is not guaranteed to be the nearest server.
Open methodology
The full measurement approach — servers, timing windows, and the exact grading thresholds behind every letter grade — is documented on our methodology page. You can also click the ⓘ icon next to your test result for the exact parameters used. We believe a speed test you can't audit isn't a speed test you should trust.