Fast internet over cable but slow over Wi-Fi: finding the cause

If the connection is fast when the computer is plugged in with a cable, the line and your provider aren't the problem: the Wi-Fi is. Here's how to confirm it and improve things.

Measure to compare

Run a speed test over a cable next to the router, then over Wi-Fi next to the router, then over Wi-Fi in the room where things are slow. Note all three results.

Reading the results

• Wi-Fi slow even next to the router: a setting or an old device. Restart the router, check that your device connects on 5 GHz if it can, and that the router is up to date.
• Wi-Fi fine next to the router but slow further away: distance and obstacles. Load-bearing walls, concrete floors, mirrors and fish tanks weaken the signal a lot.

Solutions, from cheapest to most expensive

• Move the router: up high, in the middle of the home, not inside a closed cabinet.
• Use the 5 GHz band for nearby rooms (faster) and 2.4 GHz for distant ones (longer range).
• Change the Wi-Fi channel if many neighbours use the same one.
• Add a range extender or, better, a mesh Wi-Fi system.
• For a desk computer, an Ethernet cable or powerline adapters remain the most reliable.

Share your three test results in a reply and we'll tell you which fix to try first.