How to compare router latency under load

One router may feel faster during a video call or game, even when both show similar internet speeds. To find out whether it handles busy connections better, compare the extra delay each router adds while data is moving.

The Bufferbloat Test measures how much latency grows during downloads and uploads, then gives a grade from A+ to F. A fair comparison depends on keeping everything else as similar as possible.

Compare the routers under the same workload

1. Decide what you want to compare. For the clearest comparison of router queueing, connect the same computer to each router with Ethernet. Keep the same modem, internet plan, computer, Ethernet cable, and cable length. Change only the router.
2. Close or pause activities that use the internet. Stop file downloads, video streams, cloud backups, and software updates on all devices using the connection. Do not run another speed test at the same time.
3. Open the Bufferbloat Test and run it on the first router. Note the grade and the latency increase reported during download and upload activity. Use the same browser and computer for both tests.
4. Switch to the second router without changing the modem, computer, cable, or test setup. Run the same test and record the results in the same way.
5. Repeat each test at least three times, alternating which router you test first. Compare the middle result from each set, rather than relying on one run that could be affected by a brief internet slowdown.

If you specifically want to compare Wi-Fi, test both routers wirelessly from the same spot and with the same computer. Keep the distance, room, and device orientation consistent. Use the same Wi-Fi band where possible. This compares the whole wireless experience, including the radio link, rather than only how each router handles queued traffic.

What the results mean

One router adds less delay in repeated tests

If the same router consistently shows a smaller latency increase under load, it is handling this test workload better. This can make calls, games, and remote sessions feel more responsive while someone is downloading or uploading. It does not guarantee the same result with every device or internet plan.

The grades match, but the measurements vary

A grade summarizes a range of results, so it may not show a small difference between routers. Compare the latency increases shown by the test and look for a pattern across repeated runs. If the values overlap or switch order each time, the comparison is inconclusive.

Both routers have low delay when idle, but it rises under load

This points to delay that appears when the connection is busy, sometimes called bufferbloat. It may come from the router, the modem, or the internet connection. Test over Ethernet first, then repeat at another time to see whether the result follows one router or changes with network conditions.

One router is worse only over Wi-Fi

The difference may be the wireless connection rather than traffic handling. Distance, walls, interference, and band selection can all change latency. The browser cannot read Wi-Fi signal strength in dBm, but the test can show how the connection behaves. For more detail on interpreting a grade, see What an A+ bufferbloat grade actually means.

How to fix inconsistent results

1. Stop background traffic. Pause cloud sync, downloads, streaming, and automatic updates on every device you can. A single device uploading photos can affect the result for the whole network.
2. Use the same connection type. Ethernet removes many Wi-Fi variables. If you are testing Wi-Fi, confirm the active connection before each run. On Windows 11, check Settings › Network & internet › Wi-Fi. On macOS, check System Settings › Network › Wi-Fi.
3. Keep the test path unchanged. Use the same modem, Ethernet cable, computer, browser, and test location. If a modem and router are combined in one device, note that you are comparing the full gateway, not just its router functions.
4. Test at similar times. Internet congestion can change between runs. Test both routers close together, alternate the order, and repeat later if the results are close.
5. Check traffic management settings. Some routers offer QoS or smart queue management, which controls how traffic waits when a connection is busy. If you change one of these settings, repeat the same test with it on and off. Do not change several settings at once, or you will not know which change mattered.
6. Update router software only after saving your baseline. A firmware update can change routing or traffic management behavior. Record the existing results first, update using the manufacturer's instructions, then run the same comparison again.

Separate router performance from Wi-Fi performance

Ethernet is the best starting point when you want to isolate how the routers handle a loaded internet connection. It avoids differences in radio coverage, channel interference, and signal strength. If a router performs well over Ethernet but poorly over Wi-Fi, investigate placement and wireless conditions before concluding that its latency handling is weak.

A browser test measures the connection between your device and the test service, not every possible route or application. A repeatable difference is useful evidence, but it does not prove that one router will be faster in every room or for every kind of traffic.