Does the microwave kill your Wi-Fi?
The video call freezes every time someone reheats coffee. It's not your imagination, and the fix is usually free.
Some people notice a pattern: the Wi-Fi in or near the kitchen goes bad for exactly as long as the microwave is running. It sounds like an urban legend, but the physics is real, and the fix is usually simple.
Why a microwave oven interferes
A microwave oven heats food with radio energy at about 2.45 GHz, which sits right in the middle of the 2.4 GHz Wi-Fi band. The oven's metal box and door mesh keep almost all of that energy inside, but "almost all" of a lot of power is still enough to drown out a nearby Wi-Fi signal, which is tiny by comparison.
So while the oven runs, devices on 2.4 GHz near the kitchen can see:
- slower speeds;
- response times that jump around;
- lost packets, and in bad cases a dropped connection.
The moment the oven stops, everything returns to normal.
What it doesn't affect
- 5 GHz and 6 GHz Wi-Fi. The oven's energy is nowhere near those bands. Devices on 5 GHz barely notice.
- Rooms far from the kitchen. The effect fades quickly with distance and walls. If the whole house slows down, the microwave is probably not the only thing going on.
- Your internet line. It's a local radio problem, not a provider problem.
Simple fixes
- Keep the router out of the kitchen, and not on the other side of the kitchen wall either. Routers often end up there because the line enters nearby.
- Put nearby devices on 5 GHz. A laptop on the kitchen table, a smart speaker on the counter: if they support 5 GHz, they're immune.
- Mind the line of sight. A device that sits so the microwave is between it and the router gets the worst of both: interference and an obstacle.
- Check the oven if the effect is strong. Some interference nearby is normal. If the oven knocks out Wi-Fi across several rooms, the door seal may be worn, and it's worth having the appliance checked.
Smart home devices are the usual victims, because many of them only work on 2.4 GHz. See 2.4 GHz vs 5 GHz by room for choosing bands by location.
Test it in one minute
Run the same connection check near the kitchen twice: once with the microwave off, once with it on for a minute with a cup of water inside. WiFi Heatmap shows response time, its variation and lost requests, which is exactly where microwave interference shows up. If the numbers only fall apart while the oven runs, you've found the culprit. If they're bad either way, look at the kitchen's other problems: tiles, appliances and the distance from the router.