Problems · How to check
Can I stress test my GPU online without downloading anything?
Yes. Browsers draw 3D graphics through WebGL, which runs on your graphics card rather than your processor, so a web page can put a real, sustained load on the GPU and time how fast it finishes each frame. Nothing is installed and the test stops when you close the tab.
What a browser cannot do is read the card's sensors. There is no temperature, fan speed, power draw or utilisation figure available to a web page, so an honest online test measures what the card delivered over time and infers heat from any loss, rather than quoting numbers it never read.
First, notice when it happens
The causes, ranked
1. You want a quick, install-free check of a card's sustained performance
most commonHow to confirm it
Testing a used machine, a work laptop you cannot install software on, or a friend's PC.
The fix
Run a browser test with the tab in front and the charger connected, and read the sustained figures rather than the opening peak.
2. The browser is not using the GPU you think
commonHow to confirm it
Frame rate is far lower than expected, or the test reports a basic or software renderer. Laptops with two graphics chips often default the browser to the integrated one.
The fix
Turn on hardware acceleration in the browser settings, and on a dual-GPU laptop assign the browser to the high-performance GPU in the operating system's graphics settings.
3. You need sensor readings or extreme-load validation
occasionalHow to confirm it
You are validating an overclock or need temperature and power data.
The fix
Use a native tool alongside the vendor's monitoring software. A browser test complements it; it does not replace it.
Measure it instead of guessing
SystemCheck's GPU raster stage renders a fixed 3D scene at 1600 by 900 through WebGL2 and times every frame to completion. The soft-shadow test loads the card with real-time PCSS against hard shadows, and the path-tracing stage adds the heaviest load a browser can give a GPU. The graphics backend in use is recorded with every result.
What software cannot tell you here
- Temperature, hotspot temperature, fan speed, power draw or utilisation. No browser exposes them.
- Absolute performance comparable with native benchmarks. Browsers add overhead and time the GPU differently, so compare your own runs in the same browser.
Asked, in people’s own words
- Does WebGL use the GPU?
- Yes. WebGL draws through the graphics card, and WebGL2 exposes enough of it for real rendering workloads. If hardware acceleration is off, the browser falls back to software rendering on the processor, which is much slower.
- Is an online GPU test accurate?
- It is accurate for what it measures: how fast your card finishes a fixed workload in that browser, and whether that holds. It is not directly comparable with native benchmark scores.
- Which browser is best for a GPU test?
- Any current Chrome, Edge, Firefox or Safari works. Results differ a little between browsers because they time the GPU differently, so keep to the same browser when comparing runs.