Breathing Test
Check whether screen brightness pulses periodically and assess backlight stability.
▶ Start test · Breathing
Watch the static gray screen for ~10 seconds and judge whether the brightness pulses periodically.
💡 Operation tips
- Click the right half of the screen to move to the next view; when the current project’s views are done it advances to the next project, and when every project is finished it exits fullscreen automatically.
- Click the left half of the screen to go back to the previous view; at the very first view it stops.
- After entering fullscreen, the top label and bottom buttons auto-hide after 3 seconds so you can view the screen unobstructed.
- Hover in the bottom-centre of the screen for 1 second to bring the label and buttons back; move away and they hide again after 1 second.
- The breathing test ends automatically after about 10 seconds.
{"mode":"breathing","basePath":"/screen","dict":{"mode":{"base":"All","purecolor":"Pixels","backlight":"Backlight","interference":"Interference","focus":"Focus","contrast":"Contrast","grayscale":"Grayscale","saturation":"Saturation","breathing":"Breathing"},"startAll":"Run the full screen check","startAllSub":"Start with the solid-color test, then work through all 8 checks in order. Click the screen or press Space to move to the next test project.","startSub":"Start test","stepLabel":"a total of {n} steps","fullscreenFail":"Could not enter fullscreen — continuing in windowed mode (patterns still display correctly).","prevView":"Previous view","nextView":"Next view","exitView":"Exit test","nextProject":"Next project","instr":{"purecolor":"Scan the screen for bright, dark or tinted (stuck) pixels. Use the arrow keys to switch colors.","backlight":"Look for light leaking from the edges and corners. Arrow keys toggle between black and gray.","interference":"Watch for moiré, streaks or related interference. Arrow keys switch patterns.","focus":"Check whether text, lines and shapes are crisp and sharp. Arrow keys switch modes.","contrast":"Assess the black-to-white gradient and tonal depth. Arrow keys flip the gradient direction.","grayscale":"Check that the gray steps are smooth with no banding. Arrow keys flip the gradient direction.","saturation":"Judge how vivid and even the saturated colors are. Arrow keys switch between colors.","breathing":"Watch the static gray screen for ~10 seconds and judge whether the brightness pulses periodically."},"colorName":{"black":"Black","white":"White","gray":"Gray","red":"Red","green":"Green","blue":"Blue","yellow":"Yellow","magenta":"Magenta","cyan":"Cyan"},"patternName":{"checkerboard":"Checkers","lines-h":"H-lines","lines-v":"V-lines","grid":"Grid"},"direction":{"left-to-right":"left to right","right-to-left":"right to left","dark-to-light":"black left · white right","light-to-dark":"white left · black right"},"focus":{"large":"Large text","small":"Small text","lines":"Thin lines","grid":"Fine grid","circles":"Circles","largeTitle":"Focus test","smallTitle":"Small-text sharpness","linesTitle":"Thin-line sharpness","gridTitle":"Fine-grid test","circlesTitle":"Circles & curves","vert":"Vertical lines","horiz":"Horizontal lines","diag":"Diagonal lines","fineGrid":"Fine grid (1px)","fineGrid2":"Ultra-fine grid (0.5px)","concentric":"Concentric circles","waves":"Wave lines","largeHint":"Check that large-letter edges are crisp, with no blur or ghosting.","smallBody1":"A paragraph for judging small-text sharpness. Look at whether the letter edges are crisp and the spacing even.","smallBody2":"The quick brown fox jumps over the lazy dog. 0123456789","smallBody3":"Smallest text — gauge readability and clarity at the minimum size."},"breathingTitle":"Breathing test","breathingEnd":"s until it ends automatically","tipsTitle":"Operation tips","tips":["Click the right half of the screen to move to the next view; when the current project’s views are done it advances to the next project, and when every project is finished it exits fullscreen automatically.","Click the left half of the screen to go back to the previous view; at the very first view it stops.","After entering fullscreen, the top label and bottom buttons auto-hide after 3 seconds so you can view the screen unobstructed.","Hover in the bottom-centre of the screen for 1 second to bring the label and buttons back; move away and they hide again after 1 second.","The breathing test ends automatically after about 10 seconds."]}}
Breathing effect & backlight stability
The breathing effect is a periodic darkening and brightening of the screen, like the display “breathing”. It usually comes from an unstable backlight or power supply.
Causes of the breathing effect:
- PWM dimming: low-frequency pulse-width modulation produces perceivable brightness flicker, especially below 200 Hz.
- Unstable power: a poor adapter or fluctuating voltage can make backlight brightness waver.
- Adaptive brightness: some monitors’ auto-brightness can make brightness drift frequently.
How to check:
- Watch the gray screen for 10 seconds and note whether brightness changes rhythmically.
- Turn off the monitor’s adaptive brightness and re-test.
- Point a phone camera at the screen — visible bands mean low-frequency PWM.
FAQ
What is the breathing effect?
The breathing effect is a periodic rise and fall of screen brightness, like the display “breathing”. This tool shows a static gray screen for 10 seconds so you can judge whether the effect is present.
What causes it?
Mostly low-frequency PWM dimming (especially visible below 200 Hz), an unstable power supply, or the monitor’s adaptive-brightness feature stepping in too often.
How can a phone help me check?
Point your phone camera (in a fast-shutter mode) at the screen and watch the viewfinder — if visible light/dark bands appear on a solid color, low-frequency PWM is present.
Is it still usable if I see it?
In most cases it won’t stop normal use, but long-term low-frequency flicker can strain your eyes. Try disabling adaptive brightness, raising the brightness (some PWM runs faster at higher brightness), or choosing a DC-dimming (flicker-free) monitor.