?Troubleshooting wifi by serving up a local Pi

Speedtest servers on the Internet do not confirm a local problem. If you speed is slow then that does not mean your last mile link is slow. It might be the local wifi.

You can confirm you signal strength but that isn't a clear indication. The best is to perform a local performance test.

Enter iperf3. Its available in most linux repositories including the one for the Raspberry Pi. So the tip is to dedicated a Pi to this task and to use it to confirm whether there is a local wifi problem.

Get the latest Windows version from here and the one for the following these instructions.. The android one while on that iphone/ipad use this.

That last app describes it well:

Online performance tests will tell you how fast your Internet connection is overall, but your service provider's speed is not the only factor: Wifi itself can significantly affect speed, latency and reliability. And with broadband Internet connections getting faster and faster, Wifi usually already is the bottleneck.