Control the testing conditions
Running a speed test seems simple, but getting an accurate and consistent measurement requires controlling several variables. If you run a test on a phone in the kitchen and then on a laptop next to the router, the results will vary widely due to distance and local Wi-Fi conditions rather than your actual internet line quality.
To get a baseline measurement, test your speed using a wired Ethernet connection directly to your router or modem. This eliminates Wi-Fi variables entirely. If you must test over Wi-Fi, stand close to the router with a clear line of sight, ensure no other devices are actively downloading or uploading files, and turn off any active VPNs, as they add routing delay.
Additionally, ensure that background applications are closed during the test. App store updates, cloud backups, and active browser tabs can consume significant bandwidth in the background. Controlling these variables ensures that your test results represent the actual capacity of your line rather than local network noise.
Test under network load
A standard speed test measures your latency while your network is idle. While this is a useful metric, it does not represent how your connection performs during real-world usage. When someone in your house starts a large download, your router's buffers can fill up, creating a bottleneck known as bufferbloat.
Bufferbloat causes your latency to spike dramatically under load. A connection with an idle ping of 15 ms can jump to over 200 ms when the line is saturated, causing severe lag in games and voice calls. Testing your latency while running download and upload phases reveals whether your router handles congested queues efficiently.
You can resolve bufferbloat issues by enabling Quality of Service settings or Smart Queue Management (SQM) on your router configuration page. These tools prioritize time-sensitive traffic like voice and gaming packets over bulk file transfers, ensuring your connection remains responsive and lag-free even during heavy use.