TechCompare LogoTechCompare

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 routinely run below their rated speed: plug a 144 Hz panel into HDMI 1.4 instead of DisplayPort and you silently drop to 60 Hz. 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

The browser exposes no direct 'tell me the refresh rate' API. The detector counts requestAnimationFrame callbacks over a sustained window of several seconds, then divides by elapsed time. Modern browsers gate rAF on the display's VSync, so the count matches your actual display refresh rate within roughly 1 Hz. For the most accurate read, an optional display capture upgrade uses getDisplayMedia to measure frame presentation timestamps directly, which catches cases where the browser throttles rAF independently of the panel (background tabs, power saving, multi-monitor setups where the panel runs faster than the focused window).

Why a 144 Hz monitor might read 60 Hz here

If your monitor is rated for high refresh but the detector returns 60, the most likely causes are the cable (HDMI 1.4 caps most panels at 60 Hz; use DisplayPort or an HDMI 2.1 cable), Windows not being set to the panel's native rate (Settings > System > Display > Advanced display > Refresh rate), or the GPU not sustaining the rate so VRR drops the panel back. 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 the wrong cable (HDMI 1.4 caps at 60 Hz on many monitors, you need DisplayPort or HDMI 2.1 for high refresh), Windows isn't set to the panel's native refresh rate in Display > Advanced display, or your GPU isn't feeding 144 FPS so the monitor drops to the next lower standard VRR rate.
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.

Related tools

FPS Visualizer

Visualize the impact of different FPS settings on your game experience.

Use tool ➜

Display Bandwidth Calculator

Check if your HDMI/DP cable supports your resolution and refresh rate.

Use tool ➜

Screen Size Visualizer

Compare screen sizes side-by-side to visualize physical dimension differences.

Use tool ➜

PPI & Retina Calculator

Calculate PPI and Retina distance for your display.

Use tool ➜