How to run an internet speed test that tells the truth

To run an internet speed test that tells the truth, pause other downloads and streams, test close to the router or on a cable, and run the test three times at different times of day. Then compare the typical result with your plan. A single test on a phone two rooms away mostly measures your Wi-Fi, not your broadband.

What an internet speed test actually measures

A speed test sends and receives data between your device and a test server, then reports four main numbers:

Download: how fast data arrives at your device, in megabits per second (Mbps).
Upload: how fast your device can send data out.
Ping: how long a small message takes to reach the server and come back, in milliseconds (ms).
Jitter: how much the ping varies from moment to moment.

Download, upload, ping and jitter explains each number and what good values look like.

The key point is that the test measures the whole path: your device, your Wi-Fi or mobile signal, your router, your broadband line and the route to the server. A slow result could come from any of them. A good test is set up to rule out the parts you are not trying to measure.

Before you start

Pause other traffic. Stop downloads, cloud backups, game updates and streaming on every device in the home. They share the same connection.
Close apps on the testing device. Background apps can use data while the test runs.
Turn off any VPN. A VPN adds an extra hop and can cut speed a lot.
Know your plan. Find the download and upload speeds your provider says you should get. Plans are often sold as "up to" a figure, so check what minimum or typical speed they quote.

How to run an internet speed test, step by step

Test the line first. If you can, connect a laptop to the router with a network cable and test. This shows what your broadband delivers without Wi-Fi in the way.
Test over Wi-Fi next to the router. Stand in the same room, with nothing between you and the router.
Test where you actually use the internet. Your desk, sofa or bedroom. The gap between this and the near-router result is the cost of your Wi-Fi.
Run each test at least three times, a minute or so apart. Use the middle result, not the best.
Repeat at a busy hour. Evenings are peak time for many networks. A big drop then suggests congestion.
Write everything down: time, place, connection type and all four numbers.

For mobile data, turn Wi-Fi off first, and note your signal strength in dBm and network type along with the result.

Common mistakes that skew results

Testing only on Wi-Fi far from the router, then blaming the provider.
Testing while someone is streaming in 4K or the console is downloading an update.
Running one test and treating it as fact. Results vary from minute to minute.
Comparing Mbps with MB/s. Download managers often show megabytes per second. One byte is eight bits, so 8 MB/s is about 64 Mbps.
Using a very old device. Older phones and laptops may not support the Wi-Fi speeds your router offers.
Ignoring the server. A test server far away gives higher ping and sometimes lower speed. Most tests choose a nearby server automatically, which is what you want for checking your line.

How to read your results

Compare your results with your plan and with each other.

Cable result close to your plan: your broadband is fine. Any slowness is Wi-Fi or the device.
Cable result well below your plan: the line or the router may have a problem. Restart the router and test again before contacting your provider.
Good near the router, poor in other rooms: a coverage problem. Router placement, channels or mesh are the next things to look at.
Good at noon, poor at 8 pm: congestion on your provider's network or on your local Wi-Fi.
Good download but poor upload: normal on many plans, but a problem for video calls and cloud backups.

If speed tests look good but everything still feels slow, the cause is often delay rather than raw speed. Fast speed test but slow apps covers that case. For a full checklist, see why is my internet so slow.

Keep a record

If you need to raise a problem with your provider, a short log of internet speed test results with times, places and connection types is far more persuasive than a single screenshot. It also shows you whether a change you made helped.

How CellRadar helps

CellRadar has a speed test that measures download, upload, ping and jitter on Wi-Fi or mobile data. Alongside it, the live signal readout and Wi-Fi Meter show whether a weak signal explains a poor result, and the Network Doctor runs step-by-step checks with a plain-language verdict on why things feel slow. It measures and explains; it does not make the connection faster.

Frequently asked questions

Why are my speed test results different every time?

Speed varies with network load, Wi-Fi conditions and what else is using your connection. Run three tests and use the middle result.

Should I test on Wi-Fi or with a cable?

Both. A cable test shows what your broadband delivers, and a Wi-Fi test in your usual room shows what you actually get.

Is it normal for upload to be much lower than download?

On many home broadband and mobile plans, yes. Check your plan's quoted upload speed to see what to expect.

Can a speed test use up my mobile data?

Yes. A single test can use a noticeable amount of data on a fast connection, so be careful on a limited plan.