FPS Tester

Frames per second, measured from inside the page

This counts how often your browser is able to draw a new frame. It asks the browser to call it before each repaint, measures the gap between calls, and turns that into a rate.

What the four numbers mean

• Now — the rate implied by the most recent frame alone. It jumps around, which is normal.
• Average — over the last few hundred frames. The headline figure.
• Worst frame — the single longest gap recorded. One bad frame is often a background task rather than a real problem.
• 1 % low — the rate you are getting in the worst one per cent of frames. This is the number that correlates with how smooth something actually feels, and it is why a game can average 120 FPS and still stutter.

Why it usually reads 60

Browsers cap animation at the display's refresh rate. On a 60 Hz screen you will see 60 and no more, no matter how fast the hardware is. On a 120 or 144 Hz display you should see that figure instead, which makes this a quick way to confirm a high-refresh monitor is actually running at its rated speed rather than defaulting to 60.

Many monitors ship set to 60 Hz even when they support more. If this reads 60 on a display you bought for 144, the setting is worth checking.

What this cannot tell you

This is the browser's frame rate, not your graphics card's. A game running full screen has a completely different performance profile, and a browser tab is throttled when it is in the background. Treat this as a display and browser check rather than a benchmark of your hardware.

How to use it

1. Leave it running for a few seconds so the average settles.
2. Compare Now against the average. Large swings mean something else is competing for the processor.
3. Watch the 1 % low. If it is far below the average, you are getting stutter even though the headline figure looks fine.
4. Add some load to see how the rate holds up when the page is animating a few hundred elements.

Common uses and tips

• Checking a high-refresh monitor is set correctly, which is the most useful thing this tool does.
• Diagnosing browser stutter. A tab that will not hold 60 FPS on a simple page usually has an extension or a heavy background tab to blame.
• Comparing browsers on the same machine.
• Checking battery-saver behaviour. Many laptops drop the refresh rate on battery, and this makes that visible.

What this tool can and cannot see

Everything here runs in your browser. Nothing about your keyboard, mouse or keystrokes is sent anywhere, stored, or logged — the page has no server to send it to.

What the browser gives a web page is also limited by design. It can see that a key was pressed and which one, but not what kind of switch it uses, its firmware, or anything about the device beyond what the operating system reports. A web page cannot tell a mechanical keyboard from a membrane one.

Questions people ask

Why does it show exactly 60?

Because the browser caps animation at your display's refresh rate. A 60 Hz screen cannot show more than 60 frames a second.

I have a 144 Hz monitor but see 60.

The display is probably set to 60 Hz in your operating system's display settings. Many monitors ship that way.

What is the 1 % low?

The frame rate during the worst one per cent of frames. It matches how smooth something feels far better than the average does.

Does this measure my graphics card?

No. It measures the browser's frame rate, which is capped by the display and affected by other tabs. A full-screen game behaves quite differently.