Frame rate test
Live frame rate, 1 per cent lows and frame pacing under a load you choose, for working out whether your browser and GPU are keeping up.
- Median
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- 1% low
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- Worst frame
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- Dropped
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Each bar is one frame, newest on the right. Green is within 20 per cent of the median frame time, amber within 50 per cent, red beyond that.
How to run this test
- Press Start with the load set to None. This is your baseline: what the browser manages with nothing else going on.
- Watch the frame-time graph rather than only the number. Even bars mean even pacing, which is what smoothness actually is.
- Raise the load one step at a time and watch where the frame rate stops holding and the 1 per cent low starts falling away from it.
- Leave it running for at least thirty seconds at each level. Thermal throttling takes time to show up and is invisible in a five second run.
- If the baseline is already low, check the refresh rate test first, a browser capped at 60 Hz will report 60 FPS here no matter how fast your hardware is.
What a problem looks like
- Frame rate sits well below your refresh rate with no load
- Something is capping the browser. The usual culprits are disabled hardware acceleration, a battery-saving power mode, a remote desktop session, or a browser extension doing work every frame. Check the refresh rate test to see whether the cap is in the browser or the display mode.
- The average holds but the 1 per cent low collapses
- The classic signature of stutter. Most frames arrive on time and a small number arrive very late, which is far more noticeable than a slightly lower average. Look at the red bars on the graph to see how often it happens.
- Frame rate degrades steadily over a long run
- Thermal throttling, most likely. Laptops and phones both do this. If the number starts strong and sags after a minute or two under load, the hardware is protecting itself rather than failing.
- Regular, evenly spaced spikes
- Something on a timer is interrupting the render loop: a background sync, an extension, or an antivirus scan. Regular spacing is the giveaway, since genuine rendering load produces irregular spikes.
- Smooth bars and a number that matches your refresh rate
- The result you want. The browser is delivering a frame every refresh interval with consistent pacing, which is what smooth motion is made of.
What to do next
If something looks wrong, check it again in a normally lit room and from straight on, then check whether it appears on a second device. If it only happens on this screen and you are still inside the return window, that is the time to contact the retailer.
Questions people actually ask
How is this different from the refresh rate test?
The refresh rate test answers what mode your display is in, using a median over a fixed run so that a stall cannot distort it. This one answers whether your browser and GPU can keep up, live and under a load you choose. Same underlying timing, different questions.
What is a 1 per cent low?
The average frame rate across the slowest one per cent of frames in the buffer. It describes the worst moments rather than the typical one, which is why it correlates much better with whether motion feels smooth than the headline average does.
Does this tell me my gaming frame rate?
No. This measures a canvas workload in a browser tab, which has almost nothing in common with a game engine talking to your GPU directly. Use your game built-in counter or an overlay tool for that. What this does tell you is whether the browser itself is rendering smoothly.
Why does the frame rate never go above my refresh rate?
Because the browser render loop is synchronised to the display. A page cannot paint faster than the compositor allows, no matter how much headroom the hardware has, so the ceiling here is always your current refresh rate.