Flicker, BFI & Motion Clarity Tests
Twenty-three test videos for PWM brightness flicker, black frame insertion, strobe backlight and pixel-inversion artefacts - useful for tracking down eye strain, and for comparing a monitor's BFI/strobe modes for motion clarity.
What these files actually are
A few of these use rapid brightness changes to make flicker visible - stop immediately if you are sensitive to flashing content. The rest are static or slow-changing reference patterns. All are free to download, unwatermarked, need no attribution, and are listed with a SHA-256 hash and VirusTotal link.
Common use cases
Diagnosing eye strain
Check whether PWM brightness flicker could be contributing to eye fatigue at your usual brightness level.
Comparing BFI/strobe modes
Toggle your monitor's black-frame-insertion or strobe backlight setting while this plays to compare motion clarity.
LCD Pixel Inversion Test
Only valid at native resolution, 1:1, no scaling. If this fine checkerboard shimmers or flickers strongly, your panel's voltage inversion scheme is interacting with the pattern.
Pixel Walk Test Pattern
Only valid at native resolution, 1:1, no scaling. Four fine patterns, 15 seconds each - some will flicker more than others depending on your panel's inversion scheme.
Monitor Inversion Flicker Test
Only valid at native resolution, 1:1, no scaling. A 2px alternating checkerboard - visible shimmer indicates inversion artifacts.
Checkerboard Flicker Test
Only valid at native resolution, 1:1, no scaling. A coarser 4px checkerboard for panels that pass the 1px test.
LCD Voltage Inversion Artifact Test
Only valid at native resolution, 1:1, no scaling. 1px vertical line pairs - the classic pattern for dot/column inversion artifacts.
Fine Pattern Flicker Test
Only valid at native resolution, 1:1, no scaling.
Horizontal Line Inversion Test
Only valid at native resolution, 1:1, no scaling. 1px horizontal line pairs - targets row inversion schemes.
Vertical Line Inversion Test
Only valid at native resolution, 1:1, no scaling. 1px vertical line pairs - targets column inversion schemes.
Screen Flicker Test – Monitor and Smartphone
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Low-amplitude flicker stepping through 2-30Hz. Wave a pencil in front of the screen or film in slow motion.
PWM Dimming Test Pattern
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Film the central window at several shutter speeds while lowering your screen brightness - dark bands are PWM dimming.
Low Brightness Flicker Test
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Set your display to minimum brightness - PWM flicker is strongest there.
Camera Flicker Test for Monitor
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Point your phone camera at the screen and vary shutter speed - banding in the camera preview reveals flicker.
Rolling Band Test – Screen Refresh and Camera
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video. Rolling bands in a camera preview come from the interaction of refresh rate and shutter - change shutter speed and watch the bands move.
LED Flicker Test Video
Results depend on your camera, shutter speed, room lighting, mains frequency and brightness setting - do not draw hard conclusions from one video.
OLED Near Black Flicker Test
Near-black levels alternating by a few codes - VRR OLEDs often flicker here. View in a dark room.
Black Frame Insertion Motion Test
BFI trades brightness and adds flicker for clearer motion - the lower panel simulates the effect. Real BFI is a display feature; enable it in your TV/monitor menu.
BFI On vs Off Motion Clarity
Toggle your display's BFI/motion-clarity mode while following the objects.
Backlight Strobing Test
Enable your monitor's strobe mode (ULMB/DyAc/ELMB) and track the striped blocks - strobing should sharpen them dramatically.
Strobe Crosstalk Test – Top Center Bottom
With strobe mode ON, compare the three rows: double images at the top or bottom (but not center) are strobe crosstalk.
Motion Blur Reduction Test
Compare each blur-reduction level of your monitor while tracking the blocks.
Persistence Blur Test
Sample-and-hold persistence blurs tracked motion even on fast panels - strobing/BFI is the only cure.
Double Image Test With BFI
With BFI/strobe active at the wrong rate, each object shows as two - adjust the strobe rate until the double image collapses.
Low Brightness BFI Test
BFI costs brightness - check whether dark content stays visible with BFI enabled.
Frequently asked questions
- Is this safe to watch?
- Yes for most viewers, but if you are sensitive to flashing content, skip this test - stop immediately if you feel discomfort.
- What does flicker look like?
- A slow-motion camera shot of your screen, or a very sensitive eye, will show visible pulsing brightness rather than a steady image.
- Which test should I start with?
- If you suspect eye strain, start with the low-brightness and PWM-related tests at your usual working brightness; use the BFI/strobe comparisons only if your monitor has that feature.
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- HDMI Signal & Chroma Processing Tests — 26 Free Videos
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