Refresh Rate Test

What refresh rate test does

Refresh rate is how many times per second a display draws a new image, measured in hertz. This measures how many frames your browser is actually presenting, which on a normal setup equals the display refresh rate, because the browser synchronises its drawing to the screen. It also counts late frames and sweeps a bar across the screen so you can judge smoothness by eye, which is often more convincing than the number.

How to use it

1. Close anything heavy running in the background, since it competes for frames.
2. Let the measurement run. Longer samples are more reliable on a variable refresh display.
3. Read the frames per second figure and the nearest standard rate it matches.
4. Watch the sweeping bar. At a high refresh rate it stays crisp; at 60Hz it visibly steps.

About refresh rate test

What the number actually measures

The page asks the browser to run code before each screen redraw and records the time between calls. Because the browser synchronises that to the display's vertical sync, the interval between calls is the display's frame interval, and its reciprocal is the refresh rate. The median interval is used rather than the average, deliberately: a single long pause while the machine does something else would drag an average down and misreport the panel entirely, where a median ignores it.

Why the result may be lower than your monitor

Several things cap this legitimately. A browser in a background tab is throttled hard, so measure in the foreground. Some browsers limit the animation callback to 60 per second regardless of the panel. On a laptop, a battery saver or power profile commonly drops the display to 60Hz until it is plugged in. And a high refresh rate monitor often ships set to 60Hz out of the box, with the higher rate needing to be selected in the operating system display settings, which catches a great many people who paid for 144Hz and have been running at 60.

Variable refresh rate, and why the number moves

FreeSync, G-Sync and adaptive sync let a display change its refresh rate continuously to match whatever is being drawn, which removes the tearing and stutter that come from a mismatch. On such a display there is no single correct answer here, and the measurement will move around. That is the feature working, not an error. A longer sample gives a more representative figure on this hardware.

What a higher refresh rate is actually worth

The visible benefit is real but subject to diminishing returns. The step from 60Hz to 120Hz is obvious to almost everyone, in scrolling and cursor movement as much as in games. From 120Hz to 240Hz the difference is much subtler and mostly matters in fast competitive play. Refresh rate is also not the same as response time: a panel can refresh 240 times a second and still smear, because response time describes how quickly a pixel changes value rather than how often it is asked to.

The moving bar, and why it convinces people

Numbers are abstract and motion is not. The bar sweeps at exactly one pass per second, so at 60Hz it advances in 60 discrete steps and at 144Hz in 144, with the same distance covered. Side by side on two displays the difference in edge sharpness is immediately visible, and it demonstrates the thing that actually matters in use: whether motion holds together or breaks into steps.