Measurements
Monitor Refresh Rate Test — Check Real Hz in Your Browser
Verify your monitor really delivers its rated Hz. We measure actual frame delivery using browser-native timing — no app or driver needed.
Before measuring
- • Close other tabs and apps — anything heavy can throttle frame delivery.
- • Make sure this tab is in focus. Background tabs run at 1 Hz on most browsers.
- • Allow the test to run for at least 5 seconds for an accurate reading.
Measured refresh rate
— Hz
— frames over — seconds
Measuring…
Smoothness reference (animation should be smooth)
Frames captured
0
Sample window
0.0 s
Frame jitter (std dev)
— ms
Common refresh rates
- 60 Hz — the floor; minimum for fluid scroll on modern OSes16.67 ms/frame
- 120 Hz — common on premium phones, MacBook Pro, ProMotion8.33 ms/frame
- 144 Hz — gaming standard for the past decade6.94 ms/frame
- 165 Hz — common gaming monitor sweet spot6.06 ms/frame
- 240 Hz — competitive FPS, esports tier4.17 ms/frame
- 360 Hz — current top tier, diminishing returns2.78 ms/frame
- 540 Hz — bleeding edge, rare in 20261.85 ms/frame
Frequently asked questions
Why is my refresh rate lower than my monitor's spec?
Most common reason: the OS is set to a lower refresh rate. On Windows, right-click desktop → Display Settings → Advanced display → set the highest available refresh rate. On macOS: System Settings → Displays → Refresh Rate. Other causes: a cable that doesn't support the bandwidth (DisplayPort 1.2 caps 4K@60, you need 1.4 for 4K@144), or the GPU port is HDMI 2.0 which limits high resolutions.
Why does my browser report a different number than the OS?
Browsers throttle requestAnimationFrame in some cases — when the tab is in a background, when the browser detects power-saving mode, or when the system is under heavy GPU load. We measure the actual frames delivered to this page, which can be lower than the monitor's true refresh rate. For the most accurate browser test, close other tabs and run this in foreground.
Does my GPU need to support the refresh rate?
Yes. The chain is: monitor capability → cable bandwidth → GPU output port → driver setting → OS setting. Any one of these can cap your effective rate. A 240 Hz monitor connected via HDMI 1.4 will run at 60 Hz max, regardless of what the monitor supports.
What refresh rate do I really need?
60 Hz is the floor — anything below feels choppy on modern OSes. 120-144 Hz is the everyday sweet spot for productivity and casual gaming. 240 Hz is meaningful for competitive FPS players. 360 Hz and 540 Hz give diminishing returns — you can perceive the smoothness, but the benefit to actual game performance is small unless you're a top-1% player.
Why do my measurements vary by 1-2 Hz?
Browsers don't deliver frames perfectly on schedule — there's always a few hundred microseconds of jitter. We average over a multi-second sample to smooth this out, but a 144 Hz monitor might be reported as 143.7 or 144.2 Hz depending on system load. The reading is reliable to within ±2 Hz.
What is variable refresh rate (VRR / G-Sync / FreeSync)?
VRR lets the monitor's refresh rate match the GPU's frame output dynamically (e.g., the monitor refreshes at exactly 87 Hz when the GPU produces 87 fps). This eliminates tearing without the input lag of V-Sync. Our test won't capture VRR behavior — it shows the static peak rate the browser is being driven at.
Related