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.
Online full-screen test
Run the test right in your browser, no download needed. Press Start, then click or use the arrow keys to switch patterns. To test a TV or projector without a browser, use the video files further down.
Click / → / Space: next · ←: previous · A: auto-play · Esc: exit
How to run the test
- Clean the screen and set the display to its native resolution with 100% scaling.
- Press Start (or pick a pattern below). The test fills the whole screen; the controls hide after a moment.
- Look over the whole screen on every pattern, from normal viewing distance and then up close.
- Press Esc to leave. Note where any defect is and photograph it on the pattern that shows it best, e.g. for a warranty claim.
Test patterns and what to look for
- UFO motion test
- Saucers move at 960, 480 and 240 pixels per second. A trail or a doubled, blurry saucer means ghosting or motion blur; jerky motion means dropped frames. The measured refresh rate should match the Hz set in your display settings.
- Gray 50%
- The classic uniformity field: look for darker corners, vertical or horizontal bands, a colour shift between areas, and image retention.
- White
- Dead pixels show up as black dots. Also look for dust behind the panel, a yellow or pink tint, and corners that are darker than the centre.
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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- Brightness & Contrast Test Patterns — 10 Free Calibration Videos
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- Monitor Test Online — Full-Screen Patterns + 38 Free Videos
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- Projector Test Patterns — 17 Free Downloads (Focus, Grid)