Test server and route
Your device exchanges data with a test server. Server load and the network path between your ISP and that server can affect the result.
Use a wired baseline when possible
If your goal is to evaluate the ISP connection, testing a capable computer by Ethernet can reduce Wi‑Fi variability. Then compare wireless results separately to understand the local radio layer.
Device capability
An older phone, slow network adapter, busy browser or 100 Mbps Ethernet interface can cap a test below the capability of the internet plan.
Repeat over time
Several tests at different times reveal more than one isolated result. If performance is consistently low only at peak times, that suggests a different pattern than random drops in one room.
Watch the units
Internet plans usually use megabits per second; file sizes are commonly shown in megabytes or gigabytes. Eight bits equal one byte before considering protocol overhead.