Testing your speed on a smartphone: a reliable method and data use
Contents
Most speed tests in the world are now run from a phone. It is convenient, but a few precautions avoid misleading conclusions.
Before the test
- Close background apps, especially those syncing photos or videos.
- Stay still: while moving, the phone switches cell or Wi-Fi access point.
- Note where you are: same room, same window, to compare from one day to the next.
- Check which network you use: the Wi-Fi or 4G/5G icon. Many "mobile" tests are actually done over Wi-Fi.
How much data does a test use?
The test downloads and uploads data for a roughly fixed time. The faster your connection, the more data is transferred.
| Measured speed | Approximate data per test |
|---|---|
| 10 Mbps | a few tens of MB |
| 50 Mbps | about 100 MB |
| 100 Mbps | about 150 to 200 MB |
| 300 Mbps | several hundred MB |
These are orders of magnitude depending on each phase's length. If your plan is limited, test occasionally rather than repeatedly. For converting Mbps and MB, read Mbps vs MB/s.
Measure your connection now. Start the test
Over Wi-Fi: mind the phone's limits
A phone often has fewer Wi-Fi antennas than a computer. On 500 Mbps or 1 Gbps fibre, a phone can top out well below, even next to the router. To know the line's real speed, test over a cable from a computer. See fibre slow on Wi-Fi.
On 4G/5G: a moving result
Mobile speed changes with signal, cell load and time of day. For a reliable picture:
- Run 3 tests a few minutes apart.
- Keep the middle value.
- Compare indoors and outdoors, morning and evening.
Reading ping on mobile
On 4G, a ping of 30 to 70 ms is common; 5G can go lower. High jitter means an unstable signal. The basics: ping, latency and jitter.
Keep a record
Our test stores your last 10 results in the phone's browser, with the date and detected provider. Add the page to your home screen to find it in one tap. If a problem persists, show these results to your provider's support.
Sources and further reading
Frequently asked questions
Do I need an app to test my speed?
No. A browser test works very well and needs no installation.
Why do two phones in the same place give different results?
Models have different antennas and support different 4G/5G frequencies and Wi-Fi standards.
Is the test reliable in battery saver mode?
It can underestimate speed. Turn battery saver off while measuring.
The SpeedFibre team Guides written and reviewed by a telecom engineer specialised in fibre optics (FTTH), with more than 8 years of hands-on network maintenance and measurement. Editorial policy.
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