Monitor Refresh Rate Test: Check Your Screen Hz

This refresh rate test shows how many times per second your screen really draws a new image, measured live in your browser. Leave the tab open for about 3 seconds and the HypestKey tool reports the refresh rate in Hz, the frame time in milliseconds, dropped frames and jitter. A 60 Hz screen shows a frame every 16.67 ms, a 144 Hz screen every 6.94 ms.

No download and no sign-up: the test runs in Chrome, Edge, Firefox and Safari on Windows, macOS, Linux, Android and iPhone. Want to estimate in-game FPS for a CPU and GPU instead? Use the FPS calculator.

How to use the refresh rate test

The whole check takes under a minute and works the same on a desktop monitor, a laptop screen or a phone. Six steps cover it:

1. Open this page in the browser you normally use and drag the window onto the monitor you want to check.
2. Close heavy tabs, video calls and games, then keep this tab in front. Do not switch away while it measures.
3. Wait 3 seconds. The first 30 frames are skipped, then the Refresh rate box fills in and updates 4 times per second.
4. Watch the moving square: smooth motion with no jumps means no dropped frames. Press Pause motion if the movement bothers you.
5. Read the verdict under the numbers. If it says 60 Hz but your monitor is rated higher, follow the Windows or macOS steps further down.
6. Press Measure again after any change, then Copy result to save the numbers for a forum post or a support ticket.

How this tool works: how does the refresh rate test measure Hz?

Browsers run a function called requestAnimationFrame once per screen refresh and pass it the exact start time of that frame. The HypestKey test records those timestamps, takes the median gap of the last 240 frames as the frame time and divides 1000 by it. A median gap of 6.94 ms gives 144 Hz.

Why the median? One slow frame of 50 ms would pull an average down by several hertz, while the median ignores a handful of outliers.

Within 3 % of a standard rate (24, 30, 48, 50, 60, 72, 75, 85, 90, 100, 120, 144, 165, 170, 175, 180, 200, 240, 280, 300, 360, 390, 480, 500 or 540 Hz), the big number snaps to that rate. Monitors rarely run at their exact nominal value: 59.94 Hz and 143.98 Hz are common, and both are really 60 and 144 Hz.

Any gap longer than 1.5 times the frame time counts as a drop. A gap of 20.8 ms on a 144 Hz screen is three frame slots, so the tool adds 2 missed refreshes. Jitter is the standard deviation of the gaps that were not drops, so a value under 0.5 ms usually means a stable signal.

Limits are real, and the test does not hide them. It reads the rate the browser paints at, not the panel electronics, so it cannot see overdrive, response time or input lag inside the monitor. Hidden tabs get throttled by every browser, so the measurement restarts when you come back to the tab. On top of that, battery saver on Windows laptops, Energy Saver in Chrome and Low Power Mode on Mac and iPhone can cap the browser at 60 or even 30 Hz.

What do the numbers in the results panel mean?

Five numbers appear after about 3 seconds. Refresh rate is the standard rate your screen runs at, frame time is the gap between two frames in milliseconds, Measured is the raw rate with one decimal, Dropped frames counts missed refreshes, and Jitter shows how even the frame gaps are, in milliseconds.

• Measured (Hz): the unrounded value. A reading of 119.8 Hz on a 120 Hz laptop is perfectly normal.
• Dropped frames: missed refreshes since the test started. Under 1 % of all frames is fine.
• Jitter (ms): how much the frame gaps wobble. Low jitter means the square moves evenly.

Below the numbers, a bar chart shows the frame time of the last 40 frames. Even bars mean steady timing; a tall red bar is a dropped frame.

What refresh rates do common monitors use?

Most office monitors and laptops run at 60 Hz, which is a new frame every 16.67 ms. Gaming monitors usually come in 144, 165, 240 or 360 Hz, and the fastest esports panels now reach 480 to 540 Hz. TVs typically run at 60 or 120 Hz, and film content is shot at 24 frames per second.

Going from 60 to 144 Hz cuts the frame time by almost 10 ms. Going from 240 to 360 Hz saves only 1.39 ms, which is why the jump feels smaller at the top end.

Why does the refresh rate test show 60 Hz on a 144 Hz monitor?

In most cases Windows or macOS is simply still set to 60 Hz. New monitors often start at 60 Hz until you pick a higher rate. The other usual causes are an old HDMI cable or port, a laptop on battery saver, a browser power mode, or the browser window sitting on a second 60 Hz screen.

• Setting: the display mode in Windows or macOS is 60 Hz. See the steps in the next two sections.
• Cable and port: HDMI 1.4 tops out around 120 Hz at 1080p and cannot do 144 Hz at 1440p. Use DisplayPort or HDMI 2.0 and newer, and plug into the graphics card, not the motherboard.
• Power mode: battery saver, Chrome Energy Saver and Low Power Mode can limit animation to 60 or 30 Hz. Plug the laptop in and measure again.
• Two monitors: drag the window to the fast screen. With mixed rates, some browsers on Windows can follow the primary display.
• iPhone: Safari on iPhone usually caps requestAnimationFrame at 60 Hz, even on 120 Hz ProMotion models, so 60 Hz there does not mean the screen is slow.

How do you check and change the refresh rate in Windows?

On Windows 11, open Settings > System > Display > Advanced display and pick a value in Choose a refresh rate. On Windows 10 the path is Settings > System > Display > Advanced display settings > Refresh rate. Rates above 60 Hz appear only when the monitor, cable and graphics driver all support them.

1. Right-click the desktop and choose Display settings.
2. If you have two or more screens, click the one you want to change at the top.
3. Scroll down and open Advanced display (Windows 11) or Advanced display settings (Windows 10).
4. Select the highest rate in the refresh rate list, for example 144 Hz, and press Keep changes.
5. Come back to this page and press Measure again.

Missing the higher rates? Update the graphics driver and look in the monitor’s own menu: some models ship with overclock or DisplayPort 1.4 mode switched off. On some Windows 11 laptops, Dynamic refresh rate lowers the rate when little moves on screen, so pick a fixed rate if results jump around.

How do you change the refresh rate on a Mac?

On macOS Ventura and later, open Apple menu > System Settings > Displays, select the display and choose a value in the Refresh Rate menu. MacBook Pro models with ProMotion offer ProMotion (up to 120 Hz) plus fixed 60, 59.94, 50, 48 and 47.95 Hz options. External monitors list the rates they support.

If the menu is missing, the display or adapter reports only one rate. USB-C to HDMI adapters are a frequent bottleneck here, since many cheap ones stop at 4K 30 Hz or 4K 60 Hz. On battery with Low Power Mode on, a ProMotion MacBook may stay closer to 60 Hz, so test once on the charger too.

Can you test FPS with this tool?

Yes, for the browser: the FPS of this tab equals your screen refresh rate when nothing slows it down, so this page works as a simple FPS checker. In-game FPS is a different number, because a game can render 300 frames per second on a 144 Hz monitor. For that, use the game’s own counter or an overlay.

On Windows, Xbox Game Bar (Win + G) has a Performance widget with an FPS readout, and Steam has an in-game FPS counter under Settings > In Game. For planning a build before you buy, the FPS calculator estimates game frame rates from published benchmarks.

What do dropped frames and jitter tell you?

Dropped frames show how often the browser missed a screen refresh, and jitter shows how uneven the frame gaps are. On an idle PC, expect close to 0 drops per minute and jitter under 0.5 ms. Numbers far above that usually come from a busy CPU or GPU, not from the monitor itself.

Typical causes are a video call in another window, a game running in the background, browser extensions, or a laptop that throttles when it gets hot. With G-Sync, FreeSync or another variable refresh mode, gaps can also vary slightly by design, which raises jitter a little without any visible stutter.

Does a higher refresh rate make you faster in games?

It shortens the wait for each new frame: from 16.67 ms at 60 Hz to 6.94 ms at 144 Hz and 4.17 ms at 240 Hz. Motion looks clearer and the game feels more responsive, but only if the PC can render about as many FPS as the monitor shows. Your own reaction time stays roughly 200 to 300 ms.

To see where the rest of the delay comes from, try the reaction time test and check how often your mouse reports with the mouse polling rate test. A new panel deserves a quick check for stuck or dark pixels too: the dead pixel test fills the screen with solid colors. All of these and more are on the HypestKey free PC tools page.