Doing a speedtest? Make sure you measure reliably

A speedtest seems simple: you press start, and a speed appears on your screen. Yet a single measurement does not always give a complete picture of the quality of your internet service. The outcome can also be affected by how you test and by the equipment in your home.

A low result therefore does not automatically mean that your internet provider is not delivering what was agreed. The cause may also be related to, for example:

• a weak Wi-Fi connection;
• being far from the modem;
• walls that weaken the Wi-Fi signal or interference in your home;
• other devices using the internet at the same time;
• old cables or outdated network equipment.

That is why it is important to check how you run the speedtest before assessing the result.

Test with a cable where possible

For the most reliable result, run the speedtest with a CAT6 cable connected directly to your internet provider’s modem. A CAT5e cable is the minimum. Cables below CAT5e cannot support high speeds.

If testing with a cable is not possible, test via Wi-Fi instead, ideally within 3 meters of your provider’s modem. Where possible, choose your Wi-Fi’s faster 5GHz band rather than the 2.4GHz band.

A test via Wi-Fi may show a lower speed than a test with a cable. Factors such as the distance from the modem, walls, interference and other devices in your home can affect the measured speed, even when the internet service itself is working properly.

If you use a Wi-Fi extender to increase coverage in your home, keep in mind that an extender does not automatically deliver a higher speed. The measured speed may even be lower if the extender is placed far from the modem or receives a weak signal itself.

Check your own equipment

A reliable measurement does not depend only on your provider’s connection. Your own device and any additional network equipment must also be able to support the speed.

If, for example, an old laptop, router, switch, network connection or cable supports a maximum of 100 Mbps, the speedtest may show a lower speed than the speed stated in your internet plan. In that case, the limitation may be in the equipment used for the test, not necessarily in the internet service itself.

Test at a quiet time and repeat the measurement

Preferably do not test while several devices in your home are using the internet at the same time, for example for streaming, video calls, gaming or downloads. This can lead to a lower measured speed, without necessarily meaning that something is wrong with your internet service.

Run the speedtest more than once and at different times. For each test, write down whether you tested via cable or Wi-Fi, which device you used, at what time you tested, and save the (test)result link.

If multiple measurements remain clearly lower than expected, even though you tested as reliably as possible, first contact your provider in writing. If you and your provider cannot resolve it together, you can then file a formal complaint with RAC.

(Sources: RAC. RAC publication period: 2026)