CrackMacCrackMac / Free tools / Screen flicker test
Screen flicker test: check flicker, refresh rate and motion
A free screen flicker test. It measures your screen's refresh rate straight away, then shows full-screen patterns that make flicker, stutter and smearing easy to see. For backlight flicker your eyes can't see, use the slow-motion camera trick below.
Your screen is refreshing at about
…
Measuring. Move the pointer around while it measures.
- Click Start. The test fills the whole screen.
- On the grey and white screens, look for pulsing or flashing brightness.
- On the moving bar, look for stutter, jumps, ghost copies or smearing.
- Repeat at low brightness. Many flicker problems only show when the screen is dim.
Finished. Saw flicker on every screen, or only along part of the screen? Here's what that points to.
The slow-motion camera trick
Some screens dim by switching the backlight on and off very fast. You can't see it, but some people feel it as eye strain. To check:
- Set the screen brightness low and show the white screen from the test.
- Film the screen with your phone's slow-motion mode, close up.
- Dark bands rolling through the video mean the backlight is pulsing. Steady brightness means it isn't.
What your results mean
- The refresh rate is lower than you expect. Check System Settings, Displays, Refresh Rate. On battery, macOS may lower it.
- The whole screen flickers in one app or after an update. Usually software. Here are the fixes to try.
- Flicker changes when you move the lid. The display cable is likely failing. More on that.
- Flicker or lines only along one edge. That part of the panel is damaged. See a flickering bottom edge.
Questions
How do I test my screen for flicker?
Run the screens on this page and look for brightness pulsing on the grey and white screens, and for stutter or smearing on the moving bar. To see flicker your eyes can't, lower the brightness and film the screen with your phone's slow-motion camera. Dark bands rolling through the video mean the backlight is pulsing.
What refresh rate is my screen?
This page measures it as soon as it loads. Most screens run at 60 Hz. MacBook Pros with ProMotion go up to 120 Hz, and macOS lowers the rate when nothing is moving, so move the pointer while it measures.
Why does my MacBook screen flicker?
Flicker that comes and goes with what's on screen is usually software or a setting. Flicker that changes when you move the lid, or that came after a drop, usually means the display cable or panel is damaged.
Is screen flicker bad for your eyes?
Visible flicker is tiring and can cause headaches. Some people are also sensitive to fast backlight flicker they can't consciously see. If your eyes hurt at low brightness, try a higher brightness setting.
Flicker only along one edge?
When flicker or lines stay in one strip of the screen, that part of the panel is damaged and the rest still works. CrackMac blacks out the strip and keeps windows, menus and the pointer away from it.
- Works on macOS 13 or later, Apple silicon and Intel.
- Free for 30 minutes of use, then a one-time price. No subscription.
- A refund within 7 days, no questions asked.