Why two tests?
A single speed test does not tell you where the problem is. By comparing a measurement taken next to the router (ideally over Ethernet) with one taken in the room where you use the internet, we separate two very different causes:
- The line, the router or the provider: speed is low even right next to the router. Changing your Wi-Fi gear will not help.
- Wi-Fi: speed is good near the router but collapses further away. Calling the provider will not help; you need better coverage.
How to run the diagnosis
- Choose your plan speed from the list.
- Stand next to the router, plug in a cable if you can, then start test 1.
- Go to the room where you work, play or watch videos, then start test 2 over Wi-Fi.
- Read the verdict: it gives the likely cause and the fixes.
During the tests, pause downloads, updates and videos on other devices.
Latency under load, the third clue
The test also measures ping while the line is busy. If it climbs sharply, this is called bufferbloat: the router queues packets. It causes game lag and video-call drop-outs when someone in the house is downloading. See reduce your ping.
What next?
- Line problem: check for throttling, then contact your provider with your saved results.
- Wi-Fi problem: read improve your home Wi-Fi and fibre slow on Wi-Fi but fast on cable.
Frequently asked questions
Do I really need a cable for test 1?
It is ideal because a cable takes Wi-Fi out of the equation. Otherwise, run test 1 over Wi-Fi one metre from the router, on the 5 GHz band.
Does the diagnosis work on 4G or 5G?
Yes with a 4G/5G router: test 1 next to the router, test 2 in the room. On a smartphone using mobile data, Wi-Fi is not involved, so test 1 alone is enough.
Are my results sent anywhere?
The two diagnosis measurements stay in your browser. As with any test, an anonymous result without an IP address may feed our statistics.
