Language: EN

Refresh Rate Test

Find out how many times per second your screen updates, in hertz (Hz). The test starts on its own: keep this tab in front for a few seconds and read your refresh rate, frame time and any late frames, with a moving block and a live graph.

Keep this tab in front and leave the mouse still for a few seconds. The reading settles after about 2 seconds.

--Hz

Measuring...

Frame time
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Frames per second
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Late or dropped frames
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Jitter
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Measured for
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Frame time is the median gap between frames. A frame counts as late when it takes more than one and a half times the median. Jitter is how much the gaps vary.

How to use it

  1. Close other busy tabs and keep this one in front, on the monitor you want to test.
  2. Wait a few seconds. The number settles after about 2 seconds of steady frames.
  3. Moved the window to another monitor or changed a setting? Press Measure again.
  4. Open full screen if you want to watch the moving block with nothing else on screen.

What the numbers mean

  • Hz: how many frames your browser draws each second, taken from the median gap between frames. Browsers draw once per display refresh, so on a normal setup this is your refresh rate. Screens rarely run at exactly a round number, so 59.94 Hz counts as 60.
  • Frame time: the time per frame. 60 Hz is about 16.7 ms, 120 Hz 8.3 ms, 144 Hz 6.9 ms, 240 Hz 4.2 ms.
  • Late or dropped frames: frames that took well over one frame time. A few are normal while the page loads or when you switch windows. A steady stream of them (red bars in the graph) means the computer is too busy or something else is interfering.
  • Jitter: how uneven the gaps are. Low jitter means smooth motion.

Why it might show less than your monitor can do

This test measures what the browser is drawing at. If that is lower than you expect, the usual reasons are:

  • The display is set to a lower rate. A new 144 Hz monitor often starts at 60 Hz. On Windows look under Settings, System, Display, Advanced display. On a Mac look in System Settings, Displays.
  • The cable or port. High refresh rates at high resolution need a port and cable that can carry them. Try DisplayPort, or a newer HDMI port and cable, and check the monitor manual.
  • Battery saving. Laptops and phones often lower the rate on battery or in low power mode.
  • Variable refresh rate. With VRR the screen can follow the content, so a quiet page may read lower or less steady.
  • The browser. Background tabs are slowed down or paused. Some browsers limit web pages on certain devices; Safari on some iPhone and iPad models with 120 Hz screens has held pages to 60 frames per second.
  • Several monitors. The browser usually follows the monitor the window is on. Move the window, then press Measure again.

Questions

How accurate is an online refresh rate test?

Very close for the rate itself: the median gap between frames is precise to a fraction of a hertz after a few seconds. What it cannot see is a display that repeats or skips frames on its own, which is rare. Use the moving block to judge smoothness with your own eyes.

Why does it say 60 Hz on my 144 Hz monitor?

Most often the display is still set to 60 Hz in the system settings, or the cable or port cannot carry 144 Hz at your resolution. Battery saver and some browsers can also hold pages to 60.

What is a good refresh rate?

For office work 60 Hz is fine. For games and fast scrolling, 120 Hz and above looks clearly smoother, and competitive players often use 240 Hz or more.

Does this work on phones?

Yes. Many phones switch between rates to save power, so you may see 60 on one visit and 120 on another. Turn off low power mode for the highest reading.

What is the difference between Hz and FPS?

Hz is how often the screen refreshes. FPS is how many new frames the computer makes. In this test they match, because the browser makes one frame per refresh. In games FPS can be higher or lower than the refresh rate.