LIVE DISPLAY DIAGNOSTICS

120Hz Refresh Rate Test

Check whether your display is actually rendering near 120Hz and compare the measured frame time with the expected 8.33 ms target.

● requestAnimationFrame● Runs entirely in your browser — no upload or external API.

Measuring your display…

--Hz

—

FPS--

Frame time-- ms

Minimum--

Maximum--

Stability--%

Samples0

Frame time history— ms

Keep this tab visible and move the browser window onto the monitor you want to test.

Is 120Hz active on your display?

A correctly configured 120Hz mode should usually measure close to 120 browser animation frames per second under stable conditions. Slightly lower or fractional values can be normal.

What should a 120Hz test show?

At 120Hz, each refresh interval is approximately 8.33 milliseconds. If the test remains near 60Hz, verify that 120Hz is selected and that your cable, dock, adapter and display input support the required mode.

120Hz compared with 60Hz and 144Hz

120Hz halves the nominal refresh interval of 60Hz and is close to the smoothness of 144Hz. It is common on modern phones, tablets, laptops, TVs and gaming displays.

FRAME TIMING REFERENCE

Understanding the result

A reading close to 60, 75, 90, 120, 144, 165 or 240 Hz usually means that mode is active. Small variations such as 143.9 Hz are normal.

60Hz16.67 ms

75Hz13.33 ms

90Hz11.11 ms

120Hz8.33 ms

144Hz6.94 ms

165Hz6.06 ms

240Hz4.17 ms

360Hz2.78 ms

Why is my result lower than expected?

Check your operating-system display settings, monitor menu, cable or adapter limits, GPU settings, power-saving mode and browser tab visibility. A 144Hz monitor can still run at 60Hz when the higher mode is not selected.

FAQ

Frequently asked questions

How do I know if 120Hz is working?+

A stable reading close to 120Hz with frame times around 8.33 ms is a strong browser-level indication that 120Hz is active.

Why is my 120Hz screen showing 60Hz?+

The device may be in a 60Hz mode, battery saver may be active, or the connection may not support 120Hz at the current resolution.

Can a browser test exactly 120Hz?+

It estimates the active cadence, but small fluctuations are normal because the browser does not read the panel controller directly.