Monitor Test: Online Full-Screen Patterns, Scaling, Subpixel & Sharpness
Thirty-eight test videos for confirming a PC monitor is running at true native resolution rather than being upscaled or stretched, plus subpixel layout, text-rendering and aspect-ratio/overscan checks - the things worth verifying right after connecting a new display.
What these files actually are
Fine lines and small text should render crisp with no colour fringing at native resolution; blur or fringing usually means the display isn't at 1:1 pixel mapping or scaling is interfering. Free download, no watermark, no attribution required, each file with a SHA-256 hash and VirusTotal link.
Online monitor test (full screen)
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
- Black
- Dead or stuck pixels show up as bright or coloured dots. In a dark room, light leaking from the edges or corners is backlight bleed (LCD) or IPS glow.
- 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.
- Red
- Every pixel should be the same red. A black or differently coloured dot means a dead or stuck subpixel.
- Green
- Green is the brightest primary, so stuck and dead green subpixels are easiest to spot here.
- Blue
- Dead blue subpixels are hard to see on white; this pattern isolates them.
- Gray 50%
- The classic uniformity field: look for darker corners, vertical or horizontal bands, a colour shift between areas, and image retention.
- Gradient
- Gray and red, green and blue ramps should be smooth. Visible steps (banding) point to a low bit depth, over-processing or a wrong colour profile.
- Black level
- Squares 1–19 on black. You should be able to tell at least the squares from 3 or 4 upward apart from the background. If they merge into black, shadows are crushed: raise brightness or black level, or check the RGB range (full vs limited).
- White level
- Squares 236–254 on white. If the brightest squares merge into white, highlights are clipped: lower contrast.
- Gamma
- Step back and squint: the block where the striped surround and the solid centre look equally bright shows your display's approximate gamma. 2.2 is the standard for PCs and the web.
- Sharpness
- 1-pixel lines and checkerboards should look crisp and even. Moiré, colour fringes or blur mean the image is scaled or sharpening is too high. Use native resolution, 100% scaling, and on TVs 'Just Scan' or 'Screen Fit'.
- Text clarity
- Small text should be crisp, without coloured fringes, on both white and black. Adjust ClearType or font smoothing and the display's sharpness.
- Grid & geometry
- Lines should be straight and evenly spaced and circles round. The red 1-pixel border must be visible on all four edges; if it is cut off, overscan is on.
Common use cases
Confirming native resolution scaling
Verify your monitor is running at true 1:1 pixel mapping rather than being upscaled or stretched.
Font and ClearType tuning
Check subpixel text rendering after changing scaling or ClearType/font-smoothing settings.
4K Resolution Test Pattern – Check Monitor Sharpness
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. Every 1px line pair should be distinct at 4K.
1080p Resolution Test Pattern
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. Every 1px line pair should be distinct at 1080p.
Monitor Sharpness Test – Fine Lines and Text
Set sharpness so fine lines are crisp WITHOUT halos around edges - over-sharpening shows outlines.
TV Sharpness Calibration Test
Raise TV sharpness until halos appear around lines, then back it off - usually near 0-10.
Black and White Line Resolution Test
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. 1-4px line pairs, vertical and horizontal.
4K Checkerboard Test Pattern
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. 1/2/4/8px checkerboards - the 1px quadrant should show texture, not flat gray.
Pixel Structure Test – Fine Checkerboard Pattern
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. A full-screen 1px checkerboard.
Chromatic Aberration and Color Fringing Test
Color fringes along the white lines and edges reveal chromatic aberration or chroma errors.
1:1 Pixel Mapping Test
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. With true 1:1 mapping the checkerboard is sharp texture; any scaling turns it to mush.
Native Resolution Test Pattern
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. Confirm your display runs at its native resolution.
Display Scaling Blur Test
Compare this pattern at 100% OS scaling vs 125/150% - blur means non-integer scaling.
1080p on 4K Monitor Scaling Test
Left: integer 2x scaling (sharp). Right: bilinear scaling (soft). Which does your setup produce?
Integer Scaling Test
Integer (nearest) scaling keeps pixels crisp; GPU 'integer scaling' options should match the left half.
Pixel Perfect Checkerboard Test
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test.
Single Pixel Line Test
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. 1px lines only - the hardest scaling case.
Windows Scaling Text Clarity Test
Compare text sharpness at 100/125/150% Windows scaling.
Mac Retina Scaling Test Pattern
Compare macOS 'looks like' resolutions - non-native choices soften this text.
Image Sharpening Halo Test
Bright or dark outlines hugging these edges are sharpening halos - lower sharpness/enhancement settings.
RGB vs BGR Subpixel Layout Test
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test. Fringe colors on left vs right edges of white lines reveal RGB or BGR subpixel order.
Subpixel Structure Test Pattern
Only valid at native resolution, 1:1 pixel mapping, no scaling. YouTube re-encodes video - download the lossless PNG for the definitive test.
Diagonal Line Color Fringing Test
Diagonal 1px lines make subpixel fringing most visible.
OLED Text Fringing Test
White-on-black text: colored edges on OLED come from non-standard subpixel layouts.
QD-OLED Text Clarity Test Pattern
QD-OLED's triangular subpixels can fringe on text edges - check at native resolution.
WOLED Color Fringing Test
WOLED's RWBG layout can tint fine white detail - compare edges of the 1px lines.
Small Font Rendering Test
How small can text stay readable on your panel?
ClearType Text Test
Run Windows ClearType tuning, then compare this card before/after.
HDMI PC Text Clarity Test
Blurry colored text over HDMI usually means the TV is not in PC mode (4:2:0 chroma).
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Download444MP4 · 1.3 MB
Red Text on Blue Background Chroma Test
The classic chroma killer: red-on-blue text is unreadable through 4:2:0 subsampling.
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Download444MP4 · 1.1 MB
Colored Small Text Readability Test
Small colored text vs gray reference - chroma subsampling blurs only the colored rows.
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Download444MP4 · 970 KB
Screen Alignment and Geometry Test
Grid, circles and diagonals for alignment - circles must be round, lines straight.
Circle Geometry Test – Check Image Stretching
If the circles are ovals, the image is being stretched - check aspect settings.
Screen Border Visibility Test
You should see the full 1px border on all four edges - missing edges mean overscan or misalignment.
TV Overscan Test Pattern
If the outer border or 2.5% markers are cut off, overscan is on - look for 'Just Scan' or 'Full Pixel'.
Safe Area Test for TV and Projector
Action-safe (90%) and title-safe (80%) boxes for video producers.
16:9 Screen Test – Aspect Ratio and Overscan
Circles round + full border visible = correct 16:9 with no overscan.
4:3 Aspect Ratio Test
A 4:3 pattern pillarboxed in 16:9 - circles must stay round in 4:3 mode.
21:9 Ultrawide Monitor Test
Letterboxed preview - download the native 3440x1440 file for your ultrawide.
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Download3440x1440MP4 · 1.7 MB
32:9 Super Ultrawide Screen Test
Letterboxed preview - download the native 5120x1440 file for super ultrawide.
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Download5120x1440MP4 · 2 MB
Frequently asked questions
- What should sharp text look like?
- Fine lines and small text should stay crisp with no color fringing; blur or fringing usually means the display is not at native resolution or scaling.
- Does this work on any monitor?
- Yes, though results are most meaningful when the display is set to its native resolution.
- Which test should I start with?
- 1:1 Pixel Mapping Test first, since scaling issues make every other test in this group harder to read correctly; then check subpixel/text clarity once you've confirmed native resolution.
More test categories
- Dead Pixel Test — Online Full-Screen Check + 33 Free Videos
- UFO Test & Refresh Rate Test — Online + 57 Free Videos
- OLED & Backlight Bleed Test — Online Full Screen + 27 Videos
- Brightness & Contrast Test Patterns — 10 Free Calibration Videos
- Flicker, BFI & Motion Clarity Tests — 23 Free Videos
- HDMI Signal & Chroma Processing Tests — 26 Free Videos
- Gaming Monitor Tests — 16 Free VRR, Ghosting & Blooming Videos
- Projector Test Patterns — 17 Free Downloads (Focus, Grid)