Speed test

Download, upload and latency between this browser and this server. It says what it measured and what it threw away, which is the difference between a number and a number you can use.

idle

download

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upload

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latency

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What this measures

Throughput between your browser and this one server, over whatever route the internet picks right now. That is not the same as the line your ISP sells you: a server in another country, a congested peering link or a busy wifi channel all show up here as a slower line. Run it twice from different places before blaming anyone.

How it avoids lying to you

· The first stretch is discarded: TCP starts slow and always drags the average down.
· Several connections at once — one alone cannot fill a fast line with distance on it.
· Those connections are timed by the clock on the wall, not by adding up their durations. Adding them up is what makes a home-made test report a quarter of the real speed.
· If the run was too short to mean anything, it says so instead of printing a number.

Why there is a cap. Measuring a line means spending bandwidth on purpose, and here that bandwidth is ours. Each address gets an allowance per hour — enough for several full runs — and the size of each chunk grows with the speed measured, so a phone on a slow connection is never sent tens of megabytes it would take minutes to swallow.

A slow line is a moment. A server going quiet is a problem.

This tells you what is happening right now, once. Monitoring is the same idea pointed at your own domains and left running: certificates before they expire, DNS records when they move, and your sending IPs against the blacklists.