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What Hz is my monitor?

Detect your screen's actual refresh rate in the browser, no software install. The detector runs for 5 seconds, then shows an FPS visualizer preset tuned to your exact rate so you can see what it really looks like.

Compare capture stream timing

The standard measurement above uses requestAnimationFrame, which can be throttled in background tabs or power-saving mode. A one-time screen capture can report the frame rate delivered by the captured video stream. That stream can be capped below your physical display refresh rate, so treat it as a secondary diagnostic rather than a panel reading.

About this tool

The refresh rate of your monitor is how many times the panel redraws the image every second, measured in Hertz (Hz). A 60 Hz monitor redraws 60 times per second, a 144 Hz gaming monitor redraws 144 times. This page detects your actual refresh rate live in the browser and opens an FPS visualizer preset tuned to that exact rate, so you can see what your real monitor does without digging through Display settings.

Knowing your real refresh rate matters for two reasons.

First, monitors often run below their rated speed: a cable or HDMI 1.4 mode can limit a 144 Hz panel depending on its resolution and timing, while DisplayPort or HDMI 2.1 may provide more headroom.

Second, the refresh rate is only one half of smooth motion. The other half is your GPU's frame rate. If your 144 Hz monitor is fed 60 FPS by an underpowered GPU, you're still feeling 60 Hz motion even though the panel is rated for 144.

How the detector works

Browsers do not expose a direct hardware refresh-rate API. This tool estimates browser animation cadence over several seconds using requestAnimationFrame. VSync often aligns that cadence with the display, but throttling, load, and power settings can change it.

Optional screen capture measures the delivered video stream separately. Capture FPS is not an independent hardware refresh reading and never replaces the animation estimate.

Why a 144 Hz monitor might read 60 Hz here

If your monitor is rated for high refresh but the detector returns 60, there are a few common causes:

  • A cable or mode that exceeds HDMI 1.4's bandwidth at that resolution (try DisplayPort or HDMI 2.1 for more headroom)
  • Windows not being set to the panel's native rate (Settings > System > Display > Advanced display > Refresh rate)
  • The GPU not producing enough frames, which can cause repeated frames or a VRR rate within the panel's supported range, not a hardware refresh-rate step-down

Less commonly, multi-monitor setups can throttle the focused window's rAF to the slowest attached display.

Frequently asked questions

How do I know what Hz my monitor is?
On Windows, open Settings > System > Display > Advanced display and look at the 'Refresh rate' dropdown. On macOS, System Settings > Displays and hold Option to see the refresh rate. This page also detects your actual refresh rate in the browser using requestAnimationFrame, which catches monitors running below their rated speed (because the GPU isn't feeding them, or the cable bandwidth is limited).
Why does my 144 Hz monitor report 60 Hz?
Three common causes: you're using a cable or display mode that exceeds HDMI 1.4's bandwidth (it can exceed 60 Hz at lower resolutions, but many 1440p and 4K high-refresh modes need DisplayPort or HDMI 2.1), Windows isn't set to the panel's native refresh rate in Display > Advanced display, or your GPU isn't producing enough frames. Low FPS can repeat frames and make motion less smooth, but it does not make the monitor change to a lower hardware refresh rate. VRR may vary within the display's supported range when it is enabled.
Is requestAnimationFrame-based refresh rate detection accurate?
Mostly yes. Modern browsers throttle rAF to the display's VSync rate (60, 120, 144, 240 Hz), so counting frames over several seconds and dividing by elapsed time gives a stable estimate that matches the actual display rate within about 1 Hz. The catch: browser background tabs, low-power mode, and some laptop displays throttle rAF below cap, so re-measure in a foreground tab to confirm.
What's the difference between screen refresh rate and frame rate?
Refresh rate (Hz) is how many times the display redraws per second, a property of the panel. Frame rate (FPS) is how many times your GPU produces a new image per second. Your effective motion clarity is the lower of the two. A 144 Hz panel only feels like 144 Hz if the GPU sustains 144 FPS, otherwise the monitor repeats frames.

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