A mobile data speed test measures 4G, 5G or LTE — the carrier path — not the router in the hallway. People mix the two constantly. A phone left on home Wi-Fi is a Wi-Fi speed test. A phone with Wi-Fi off is a cellular test. SpeedMetric’s internet speed test works in a mobile browser for either path. You have to pick which one you wanted.
Turn Wi-Fi off for a 5G speed test. Confirm the status icon. Pause cloud backups. If a VPN is on, you are measuring the VPN plus the cell path. How to check internet speed is the same hygiene on a handset. The public IP will be the carrier’s, not the home ISP’s — what is my IP.
What a good mobile result looks like
5G outdoor next to a window can look excellent. 4G in a lift can look tragic. Both can be honest. Ping on cellular is often higher than a good home fiber Ethernet run. That is delay, not a reason to shout at the home provider. Good internet speed still depends on the job: a HD stream needs download; a call needs upload and calmer ping.
Signal bars are not Mbps. One bar of 5G can beat four bars of crowded 4G, or not. Test where you actually sit, then near glass. Congestion on a cell site at a stadium is the mobile version of evening cable sag. Repeat at another hour before you assume the SIM is broken.
Phone radios and fair comparisons
Older phones may not speak the same 5G bands as a new flagship. Comparing your result with a stranger’s 5G speed test on a different corner of the city is entertainment, not science. Compare your phone in two places, or two phones on the same cell. Metered plans can incur charges when a download test runs; that cost is yours — see the disclaimer.
If you meant to measure home broadband, get back on Wi-Fi and stay there for the whole run. If the house Wi-Fi is the complaint, a cellular test cannot prove the ISP is slow. Use Ethernet or a near-router Wi-Fi test for that argument — debug the home path. Mobile data is a backup path, not a control for plaster.
When mobile looks fine and Wi-Fi does not
That pattern is useful. The phone radio works. The home air or last mile does not. Switch the Wi-Fi experiment to boosting signal or the ISP experiment to the plan versus the test. Keep the labels in the notes: “5G outdoor 14:10” versus “home Wi-Fi sofa 14:12.” Without the label, you will mix the internets again tomorrow.
Common questions
How do I run a 5G speed test on my phone?
Turn off Wi-Fi so you are on cellular, open the speed test in the browser, and tap Start. The result is the mobile path, not home broadband.
Why is mobile data slower indoors?
Buildings block radio. 5G and 4G both fade indoors. Test near a window, then where you sit. A large gap is coverage, not a broken tester.