Hz Test — Check Your Refresh Rate

Press Full Screen and let it run 10–15 seconds — the tool counts real browser frames to measure the refresh rate your system is actually sending to the panel. Works as an Hz checker for any monitor, laptop, or TV: 60, 75, 120, 144, 165, 240Hz and up.

New to this? Here’s the plain-English version.

What this test is

It measures how many times per second your screen redraws itself, in Hertz (Hz) — the number your monitor is rated at, like 60Hz, 120Hz, or 144Hz.

How it helps you

If Windows or a cable quietly capped you below that rating, you’re losing smoothness you already paid for. This confirms what you’re actually getting.

What we’re checking

Your monitor’s real, live refresh rate right now — and whether it matches the number on the box.

Detected Refresh Rate:

0 Hz

This value should match your monitor's refresh rate setting.

This test uses requestAnimationFrame to count the number of frames rendered per second. The displayed value should be very close to your monitor's advertised refresh rate (e.g., 60, 120, 144 Hz).

Press F11 or Full Screen · ← → patterns · Esc to exit

How to Read Your Hz Result

“Hz test” and “refresh rate test” mean the same thing — Hz (Hertz) is simply the unit refresh rate is measured in. The number above reflects what your current system configuration delivers to the monitor, not the maximum the panel is capable of. Run it any time you change a cable, GPU, port, or display setting and want to confirm Windows is really driving the panel at its rated Hz.

1Launch the test. Press Full Screen above. The tool measures your refresh rate by counting animation frames with the browser’s native requestAnimationFrame timing.
2Wait 10–15 seconds. The reading averages over many frames — a longer sample gives a more stable Hz number.
3Compare to your rated Hz. A 144Hz monitor should read ~144Hz, a 60Hz monitor ~60Hz. A reading within 1–2Hz of the target is normal.
4Fix a low reading. If the number is lower than expected, set the refresh rate in Windows Display Settings and check your cable type before assuming the panel is faulty.

What Higher Hz Actually Changes

Refresh rate is how many times per second the screen redraws. The practical effect is frame persistence — how long each frame lingers before the next one appears. Shorter persistence means less smearing as your eyes track motion. Here is how long a single frame stays on screen at each refresh rate:

60Hz

16.7ms

120Hz

8.3ms

144Hz

6.9ms

240Hz

4.2ms

360Hz

2.8ms

Time each frame is held on screen — shorter is smoother.

Is the Upgrade Worth It?

60Hz → 144Hz

Transformative

The single most impactful monitor upgrade. Motion is dramatically smoother and game feel improves substantially. Always worth it.

144Hz → 240Hz

Worth it for competitive

Clearly visible in fast shooters (CS2, Valorant, Apex). Real but more modest than 60→144. Recommended for competitive players.

240Hz → 360Hz+

Diminishing returns

Measurable and useful to top-tier esports pros, but most players see minimal practical gain. Optional.

One caveat: a high-Hz monitor only helps if the rest of the chain keeps up. You need a GPU that consistently exceeds that frame rate in your games, the correct cable for your resolution-and-Hz combination, and the refresh rate set correctly in your OS.

Reading Lower Than Expected? Diagnose It

144Hz monitor reads 60Hz

Cause: Windows reset the refresh rate to its 60Hz default after a cable, port, or resolution change.

Fix: Display Settings → Advanced Display → set 144Hz.

165Hz monitor reads 144Hz

Cause: An HDMI 2.0 cable caps 1440p at 144Hz.

Fix: Switch to DisplayPort 1.4 or HDMI 2.1.

240Hz monitor reads 144Hz

Cause: You are plugged into a GPU output port that maxes out below the panel’s rated Hz.

Fix: Move to a DisplayPort output (preferred over HDMI).

Reading fluctuates ±1–2Hz

Cause: Background system load or GPU power management — normal variation.

Fix: No action needed; this is expected.

Step-by-Step: Set the Right Refresh Rate

Windows

Right-click desktop → Display Settings → Advanced Display.
Under “Choose a refresh rate”, select your rated Hz.
Click Apply and re-run the test above.

GPU control panel (override)

Nvidia: Control Panel → Change Resolution → pick Hz from the dropdown.
AMD: Radeon Settings → Display → Custom Resolutions → set Hz.

Resolution	Target Hz	Minimum cable
1080p	144Hz	HDMI 2.0 or DisplayPort 1.2
1440p	144Hz	HDMI 2.0 or DisplayPort 1.2
1440p	165Hz+	DisplayPort 1.4 or HDMI 2.1
4K	144Hz	DisplayPort 1.4 or HDMI 2.1

Prefer DisplayPort over HDMI when both are available — it carries higher bandwidth and keeps latency low. Once your Hz is correct, tune motion clarity with the response time test and the ghosting test.

Refresh Rate FAQ

How do I check my monitor’s refresh rate?+

The most reliable method is the tool above — it counts real animation frames in your browser using requestAnimationFrame, so it reflects what your system is actually sending to the display. You can cross-check in Windows: right-click the desktop → Display Settings → Advanced Display, which shows the current refresh rate. Your monitor’s OSD menu usually reports the incoming Hz too.

Why does my 144Hz monitor show 60Hz?+

The most common cause is Windows resetting to 60Hz after you change a cable, port, or resolution — 60Hz is the safe default. Fix it: right-click the desktop → Display Settings → Advanced Display → Choose a refresh rate → select 144Hz. If 144Hz is not listed, the cause is almost always the cable (you need HDMI 2.0 or DisplayPort 1.2 for 1440p at 144Hz) or the GPU output port you plugged into.

What is the difference between 60Hz and 144Hz?+

At 60Hz each frame stays on screen for 16.7ms; at 144Hz it is 6.9ms. Lower persistence means smoother motion, less display lag, and crisper feedback during fast movement. The jump is immediately obvious side by side — most people describe 60Hz as feeling sluggish after using 144Hz.

Does refresh rate affect gaming performance?+

Yes, in two ways. Higher Hz lowers display lag (the delay between a frame being rendered and shown), and it shows you more frames per second, giving faster visual feedback on moving targets. It matters most in competitive shooters where reaction time is decisive. Note that you only benefit if your GPU actually produces frames at that rate.

How do I enable 144Hz (or higher) in Windows?+

Right-click the desktop → Display Settings → Advanced Display → under “Choose a refresh rate”, pick your rated Hz. If it is missing, the cause is an unsupported cable, the wrong GPU port, or a driver issue. Use DisplayPort 1.2+ for 1080p/1440p at 144Hz, and DisplayPort 1.4 or HDMI 2.1 for 1440p 165Hz+ or 4K 144Hz.

Is a browser Hz test accurate?+

Yes, to within about 1–2Hz under normal conditions. It measures the frames your OS and GPU deliver to the panel, averaged over several seconds. Let it run 10–15 seconds for a stable reading. A result that drifts by ±1–2Hz is normal; a result far below your rated Hz points to a settings or cable problem, not a faulty panel.

Does a higher refresh rate reduce eye strain?+

It can. Higher refresh rates produce smoother scrolling and cursor motion, which some people find noticeably more comfortable during long sessions — though the effect is smaller than the difference brightness and blue-light settings make. If comfort is your priority, 120Hz+ paired with a moderate brightness (120–150 nits) is a good target.

Related Monitor Tests

Response Time Test

Grey-to-grey pixel speed and overdrive tuning

Ghosting Test

Trailing artifacts and inverse ghosting

Motion Blur Test

Perceived blur during fast motion

Checking a whole new panel?

Run the dead pixel test and browse the full monitor test suite.

Monitor Pixel Test All Monitor Tests