How to Check Your Refresh Rate: Is Your Screen Really Running at 120Hz or 144Hz?
You bought a 120Hz phone or a 144Hz gaming monitor, yet motion doesn't feel any smoother. The quickest way to find out why is to measure what refresh rate the screen is actually running at. This guide explains what refresh rate means, how to measure it in a browser and read the result, and which settings and cables to check on iPhone, Android, Windows and Mac when you don't get the advertised rate.
What is refresh rate? How many times per second the screen redraws
Refresh rate is the number of times per second a screen redraws its image, measured in hertz (Hz). At 60Hz the screen updates 60 times a second; at 120Hz, 120 times. The higher the number, the smoother scrolling, mouse movement and game footage look.
| Refresh rate | Time between redraws | Common devices |
|---|---|---|
| 60Hz | About 16.7 ms | Typical phones, laptops and office monitors |
| 90Hz | About 11.1 ms | Some Android phones, VR headsets |
| 120Hz | About 8.3 ms | High-end phones and tablets, TVs for game consoles |
| 144Hz | About 6.9 ms | Gaming monitors |
| 240Hz | About 4.2 ms | Competitive gaming monitors |
A similar term is frame rate (fps). Refresh rate is how often the screen redraws; frame rate is how many images per second the game or video produces. On a 144Hz monitor, a game running at only 60fps looks only as smooth as 60fps.
How to measure refresh rate in a browser
Browsers advance page rendering in step with the screen's redraws. Recording the interval between those steps for a few seconds lets you work backwards to the screen's refresh rate. The Screen Checker's Refresh rate test measures this way for 3 seconds.
- 1
Close other apps and tabs
Heavy work in the background can make rendering miss its slot and upset the timing. Stop videos and other tabs before measuring.
- 2
Put the browser on the screen you want to test
With two monitors connected, move the browser window to the monitor you want to measure before starting.
- 3
Don't touch anything until it finishes
Avoid scrolling or switching tabs during the 3-second measurement. Browsers pause rendering for background tabs, so you won't get a correct value.
- 4
Check the result and the dropped-frame rate
You'll see the nearest standard value (60Hz, 120Hz, 144Hz and so on) and the measured value. If dropped frames are within a few percent, the display is running steadily.
The measured value may come out with decimals, such as 59.94Hz. That frequency comes from TV broadcast standards and is effectively the same as 60Hz. If the dropped-frame rate is high, the device's processing may be falling behind rather than the screen. Comparing smoothness with the moving square shows how the numbers match what you see.
Settings to check when your phone won't hit 120Hz
Phones lower their refresh rate automatically to save battery. If you're not getting the advertised value, check these settings.
- Low Power Mode / battery saver: with iPhone Low Power Mode or an Android power-saving mode on, the screen is held to 60Hz.
- iPhone "Limit Frame Rate": if this option under Settings > Accessibility > Motion is on, the maximum is 60Hz.
- Safari on iPhone: even on a 120Hz (ProMotion) display, Safari may hold page rendering to around 60Hz. That is why scrolling in apps feels smooth while a browser test reports 60Hz.
- Android display settings: depending on the model, an option called "Smooth Display", "Motion smoothness" or "Refresh rate" switches between 60Hz and a high refresh rate.
What to check when your PC monitor won't run at 144Hz
Gaming monitors often stay at 60Hz after you plug them in. Even if the monitor supports it, you only get a high refresh rate when both the PC settings and the cable are right.
- Windows: go to Settings > System > Display > Advanced display and change "Choose a refresh rate" to 144Hz or similar.
- Mac: go to System Settings > Displays, select the external monitor and change "Refresh Rate".
- Cable and port: an older HDMI cable or port can't carry a high-resolution, high-refresh signal, and the limit drops to 60Hz or so. Use DisplayPort, or the HDMI version specified in the monitor's manual.
- Graphics output: on a desktop PC, make sure the cable goes into the graphics card, not the motherboard's video output.
- Resolution trade-off: some models can't select 144Hz at maximum resolution but can at a lower one. Check the support table in the manual.
After changing settings, measure again in the browser to confirm the value went up. When you buy a monitor, check for dead pixels and uneven color at the same time as the refresh rate; the steps are in checking a new monitor for defects.
Limits of measuring in a browser
Measuring in a browser is convenient, but what it measures is the interval at which the browser renders the page. Keep in mind that power-saving behavior in the device or browser can produce a value lower than the screen can actually do.
- If the browser limits rendering, it may report 60Hz even though the screen is running at 120Hz.
- With several monitors connected, the measurement may follow the main monitor's rate.
- With variable refresh rate (G-SYNC, FreeSync and so on) enabled, the value changes with what's on screen.
For a more precise answer, combine the result with the value shown in your OS display settings or a game's frame rate counter. For what to check when buying a used phone or tablet, see checking a used phone's screen.
FAQ
- How can I check my refresh rate?
- On a PC, the OS display settings show and change the current refresh rate. On phones and tablets, a browser tool that measures the interval between screen redraws tells you the actual value, such as 60Hz or 120Hz.
- My iPhone supports 120Hz, so why does it show 60Hz?
- Low Power Mode or the "Limit Frame Rate" setting holds it to 60Hz. Safari may also hold page rendering to around 60Hz, so a browser test can show 60Hz even when apps run at 120Hz.
- My monitor is 144Hz but I only get 60Hz.
- Check that the refresh rate in your PC's display settings isn't still at 60Hz, and that the cable and port support high refresh rates. On a desktop PC, also make sure you're plugged into the graphics card.
- What's the difference between refresh rate and frame rate?
- Refresh rate is how many times per second the screen redraws; frame rate is how many images per second the game or video produces. Whichever is lower caps the smoothness.
Tools in this article
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