Why a computer throttles during long video meetings
Learn how to spot heat-related throttling during long video meetings, separate it from connection problems, and reduce the workload on your computer.
A video meeting starts smoothly, then the picture stutters, the fan gets loud, or the computer becomes slow to respond. If this happens after you have been on a call for a while, heat may be making the computer reduce its speed to protect itself. A busy app, power setting, or weak connection can cause similar symptoms.
You can look for signs of heat-related slowdown with TooLab's Overheating Test. It puts the computer under a heavy workload for a few minutes to see whether performance slows as the system heats up. The result is a clue, not a direct measurement of your computer's temperature.
Check for slowdown under load
- Open the Overheating Test on the computer that has trouble during meetings. Save your work and close other demanding apps first.
- Place the computer on a firm, flat surface with its vents clear. Start the test and let it run for a few minutes, following the test's on-screen instructions.
- Notice whether the test slows down as it continues, or whether the computer becomes less responsive and its fan gets louder. Stop if the computer becomes unusually hot, shuts down, or shows a warning.
- After the test, let the computer cool. Compare how a meeting behaves at the start with how it behaves after 20 to 30 minutes. Note whether the problem affects video, audio, or the whole computer.
A full-load test is not the same workload as a video call. It helps reveal whether sustained work may be a factor, but it cannot prove that the meeting app is throttling or identify the exact part that is hot.
What the result means
The test slows down as it runs
A slowdown under sustained load makes heat-related throttling more plausible. Throttling means the computer deliberately reduces performance to stay within safe limits. Dust, blocked vents, a failing fan, high room temperature, or dried thermal material can contribute. Check the cooling and workload fixes below, then compare the meeting again.
The test stays steady, but the meeting gets worse
The cause may be specific to the meeting setup. Video encoding, background blur, virtual backgrounds, screen sharing, and several open browser tabs can all add work. A weak or unstable connection can also make video freeze while the computer itself remains responsive. Check whether local apps and the mouse also become slow, and test connection stability separately if only the call is affected.
The whole computer slows down and the fan gets louder
That pattern can fit sustained heat or a heavily loaded processor, graphics chip, or memory. It is not proof of a fault: a meeting with high-resolution video and effects can demand more work than a simple call. Close unnecessary apps and repeat the comparison with fewer meeting effects.
The computer slows down without much fan noise
Low power mode, battery saver, a quiet fan profile, or a background task may be limiting performance. Some thin or fanless devices also reduce speed without an obvious fan sound. Check power settings and see whether the problem changes when the computer is plugged in.
How to reduce the slowdown
- Clear the vents. Use the computer on a desk or stand, not a blanket, cushion, or lap that covers its air openings. Leave space around the sides and rear, and move it out of direct sunlight.
- Lower the meeting workload. Turn off virtual backgrounds, background blur, and video filters if you do not need them. Reduce outgoing video quality in the meeting app if that option is available, and avoid sharing a high-motion screen while several video streams are open.
- Close other demanding work. Pause large downloads, game launchers, video exports, and unnecessary browser tabs. If the slowdown stops when those tasks are closed, the computer may be running out of performance headroom rather than overheating from the call alone.
- Check the power mode. On Windows 11, open Settings › System › Power & battery › Power mode and check the selected mode. On a Mac, open System Settings › Battery and check Low Power Mode. For a comparison, connect the laptop to its usual charger and retest, using a suitable surface with clear airflow.
- Restart the meeting app and computer. A restart can clear a stuck process that keeps using resources after a call. Install pending operating system, browser, and meeting app updates when you have time to restart.
- Check the cooling system. If the vents are clear but the fan rattles, stops, or stays unusually loud, have the cooling system inspected. Do not open a laptop unless you know how to do so safely and without affecting its warranty.
When it may be a hardware problem
Consider repair if the computer repeatedly slows under ordinary calls, overheats while idle, shuts down, or makes a fan grinding noise. A laptop that performs normally after cooling but slows again soon after sustained use may need cleaning or fan service. Back up important files before arranging repair, and describe what happened, how long the call ran, and whether the computer was plugged in. A browser test cannot identify a failing fan or confirm an internal temperature sensor fault.
Why a browser test cannot show an exact temperature
A browser can run a workload and reveal that performance changes, but websites generally cannot read the computer's exact CPU temperature. The operating system and device firmware control access to those sensors. Treat the test as a way to compare behavior, not as a thermometer or a diagnosis. For more on this limit, see Why browser load tests cannot show exact CPU temperature.
