How to test Wi-Fi through walls and floors

Wi-Fi works beside the router, but a connection gets slow or keeps pausing in another room. A floor, several walls, or a long hallway can weaken the connection, but distance and nearby electronics can matter too.

Use the Wi-Fi Map to compare connection quality in different rooms. The results can show you where the connection struggles and help you decide whether to move the router or add coverage.

Map Wi-Fi in different rooms

1. Open the Wi-Fi Map on the device you want to check. Keep using that same device and browser for every measurement.
2. Start near the router. Follow the on-screen instructions to measure the connection, and note the location and result so you have a baseline.
3. Take the device to the rooms you want to compare. Measure in the usual place where you use it, such as a desk or couch, rather than right in the doorway.
4. Keep the device in the same position for each measurement, and give each one the same amount of time to complete. Repeat a reading if it looks unusual.
5. Compare the rooms. Look for differences in response time, jitter, and lost requests, not just whether a page loads.

For a useful comparison, keep other conditions steady. Avoid running large downloads or video streams during the measurements. If you want to compare the effect of a closed door, take a reading on each side without moving the device to a different height or changing its orientation.

What the results mean

Connection quality drops in one room

If response time, jitter, or lost requests are noticeably worse in a particular room than near the router, the connection is less reliable there. A wall or floor may be part of the reason, but the result does not identify the building material or prove that it is the only cause. Distance, the router's position, and interference can also contribute.

Several rooms have similar results

If the readings are similar throughout the home, the walls and floors may not be causing a major change under those conditions. If internet use still feels slow, check whether other devices are using the connection or whether the internet service itself is having a problem.

Results change from one attempt to the next

Wi-Fi can vary as devices connect, traffic changes, and interference comes and goes. Repeat the measurements at another time with the same device and locations. A single short reading is not enough to prove that a room has a permanent coverage problem.

There is no signal-strength number

A browser cannot read your Wi-Fi signal strength in dBm, the radio measurement often shown by diagnostic apps. The Wi-Fi Map measures what the connection does, including response time, jitter, and lost requests. Those results are useful for comparing rooms, but they are not a direct radio-strength reading.

How to improve Wi-Fi through walls and floors

1. Check that every reading uses the same Wi-Fi network. A phone may switch to mobile data, or a computer may connect to a guest network. On Windows 11, open Settings › Network & internet › Wi-Fi. On macOS, open System Settings › Wi-Fi. On iPhone, check Settings › Wi-Fi. On Android, open Settings › Network & internet or the Wi-Fi page, depending on the device.
2. Repeat the weak-room measurement. Pause streaming and downloads, then measure again from the same spot. This helps separate a lasting coverage issue from temporary network traffic.
3. Move the router into a more open position. Put it higher than the floor, away from a cabinet, and closer to the areas where people use Wi-Fi. Avoid hiding it behind a television, inside a closet, or beside large metal objects.
4. Compare the available Wi-Fi bands. If your router shows separate network names for 2.4 GHz and 5 GHz, test both in the weak room. The 2.4 GHz band often reaches farther through obstacles, while 5 GHz can be faster nearby. If the names are combined, the router may choose the band automatically.
5. Look for nearby sources of interference. Move the router away from cordless phone bases, some Bluetooth devices, and appliances that can interfere with Wi-Fi. Retest after moving one item at a time so you can tell whether it helped.
6. Add an access point or mesh node if the layout still has a dead zone. Place it where it can still receive a good connection from the router, not at the far edge of the weak area. Then repeat the room measurements to check the change.

What the map cannot tell you

A browser-based Wi-Fi measurement checks the connection between your device and the test service. It cannot identify which wall is blocking the signal, measure radio power directly, or fully separate a weak wireless link from an internet or service problem. For a fair comparison, use the same device and test method in each room, and treat repeated patterns as more meaningful than one result.

Record the room, whether doors were open, and the time of each measurement so you can compare changes later.