GPU Stress Test: hold a steady load for up to 10 minutes
A benchmark tells you how fast a GPU is. A stress test tells you whether it stays that fast. Volume Shader keeps the same ray-marched 3D scene running for 1, 5 or 10 minutes, samples FPS every second, and compares the first 30 seconds with the last 30. If the curve sags, the card is throttling.
Pick 1 minute on a phone. Expect the device to get warm.
What the stress test shows
Everything a benchmark shows, plus the shape of the run.
FPS curve
One sample per second for the whole run, drawn as a line. A flat line is a healthy card. A line that steps down after a minute or two is a card hitting its temperature or power limit.
FPS drop
Average of the first 30 seconds against the last 30, as a percentage. This is the one number that tells you whether the GPU held its speed.
Lowest second
The worst single second of the run. A big gap between lowest and average means stutter, even if the average looks fine.
How long to run it
| Duration | Use it for |
|---|---|
| 1 minute | Quick sanity check. Phones, tablets and thin laptops; long enough to see the first throttling step on a phone. |
| 5 minutes | Most desktops and gaming laptops reach a steady temperature in about this time. Good default for a PC. |
| 10 minutes | Checking a case, a laptop cooling pad, a repaste or an undervolt. Run before and after and compare the FPS drop. |
Keep the tab in the foreground. Browsers slow down background tabs, which would show up as a fake drop.
Reading the FPS drop
| Drop | Verdict | What to do |
|---|---|---|
| Under 5% | Stable | Nothing. The cooling keeps up with the load. |
| 5% to 15% | Mild | Normal for thin laptops and most phones. Only worth chasing if you also hear the fan maxing out. |
| Over 15% | Throttling | The GPU slowed itself down to stay within its temperature or power limit. Check dust, fan curves, thermal paste age and, on laptops, the power plan. |
Limits of a browser stress test
Be honest about what WebGL can and cannot do before drawing conclusions.
- It does not read temperature, clock speed or power. Run HWiNFO or GPU-Z alongside if you want those numbers next to the FPS curve.
- The load is lighter than FurMark or OCCT. Frame rate is capped at your screen's refresh rate, so a fast card idles part of each frame. Move up to Ultra to push it harder.
- It does not test VRAM capacity or memory errors.
- A crash here is a browser or driver crash, not proof of faulty hardware. Repeat with a desktop tool before blaming the card.
Stress test versus benchmark
The 30-second GPU test on this site is a benchmark: it answers "how fast". The run is short on purpose so the number is repeatable and the GPU is still cool at the end.
A stress test asks a different question: "does it stay that fast". Heat builds up over minutes, not seconds. A card that posts a great 30-second score and then loses a quarter of it by minute five will stutter in a long gaming session even though every benchmark says it is fine.
Use the benchmark to compare devices and presets. Use the stress test to check cooling on the device you already own.
GPU stress test FAQ
Common questions about stress testing a graphics card in the browser.
Is a GPU stress test safe?
Yes. Modern GPUs throttle themselves long before they reach a damaging temperature, which is exactly what the FPS drop measures. The browser cannot override those limits, overclock, or change voltages.
How long should a GPU stress test last?
Five minutes shows whether a desktop reaches a stable temperature. Ten minutes is enough to judge a cooling change. Longer runs mostly repeat the same curve.
Why does my FPS fall during the test?
Usually heat. The GPU hits its temperature limit and lowers its clock. On laptops it can also be a power limit, or the system switching to the integrated GPU when the browser decides the dedicated one is not needed.
How is this different from FurMark?
FurMark is a native power-virus workload that pushes the card to its absolute limit and reads sensors. This test runs in the browser with no install, which also means it is capped at the display refresh rate and cannot read temperatures. It is a cooling check, not a replacement.
Can I stress test my phone?
Yes. Use the 1-minute run on Low. Most phones start throttling within the first minute, which the FPS curve will show.
Does it test VRAM?
No. The scene uses no textures, so memory capacity and bandwidth are not exercised.