Display Test (Monitor Test Patterns)
An all-in-one, full-screen display test for any monitor, laptop or TV. Step through six reference patterns — solid colors, grayscale ramps, color bars, a sharpness grid, a geometry grid and near-black/near-white contrast steps — to eyeball dead pixels, tint, backlight uniformity, banding, gamma, sharpness and edge geometry in one pass. Everything runs in your browser; nothing is uploaded.
← → ← → change pattern · Esc to exit
What each pattern checks
Dead or stuck pixels, color tint and backlight uniformity on a single flat color.
Banding, black crush and white clipping across smooth and stepped gray ramps.
Color accuracy and saturation against reference bars and a hue sweep.
Scaling, focus and convergence using a one-pixel grid and checkerboard.
Edge cropping, centering and alignment against a full-screen grid with markers.
Shadow and highlight detail in near-black and near-white steps.
Backlight bleed and near-black detail only show up in low ambient light.
Run at the panel’s native resolution and 100% browser zoom for a 1:1 pixel map.
Wipe off dust and smudges so they are not mistaken for stuck pixels.
What a display test checks
A monitor display test walks the panel through a handful of extreme, uniform patterns so faults have nowhere to hide. Solid full-screen colors expose dead or stuck sub-pixels, color tint and backlight non-uniformity. A grayscale ramp reveals banding and whether the darkest and lightest tones are crushed or clipped. Color bars check saturation and color accuracy against known references. A one-pixel grid and checkerboard show scaling, focus and convergence problems, while an alignment grid highlights edge cropping and centering. Near-black and near-white steps test how much shadow and highlight detail your gamma and contrast actually preserve.
How to run the test properly
- Dim the room. Backlight bleed, clouding and near-black detail are only visible when ambient light is low.
- Set the monitor to its native resolution and keep the browser at 100% zoom, so one image pixel maps to one screen pixel.
- Go full screen and let your eyes adjust for a few seconds on each pattern before judging it.
- Clean the screen first — dust and smudges are easily mistaken for stuck pixels on the solid-color and grayscale patterns.
- View each pattern straight on and centered; on VA and TN panels, brightness and tint shift noticeably off-axis.
Good vs bad results
On the solid-color patterns a healthy panel looks flat and even, with no bright or dark dots and no obvious color cast; faint corner glow on a black field is normal backlight bleed on LCDs, while distinct bright dots are stuck or dead pixels. The grayscale ramp should read as a smooth sweep — visible steps or colored tints in the gray indicate banding or a calibration issue, and you should still be able to separate the darkest and lightest few steps rather than seeing solid black or white. Color bars should look pure and saturated, the sharpness checkerboard should resolve to fine, even texture (not a blurry or shimmering moiré), and the geometry grid should reach cleanly into all four corners with a centered image.
When to use it
Run a display test whenever you are buying or returning a monitor, laptop or TV — checking a new panel within the return window is the cheapest insurance against dead pixels and heavy backlight bleed. It is also worth a pass after transporting or mounting a display, after a driver or cable change, or whenever colors, sharpness or uniformity suddenly look off. For a deeper look at a single aspect, pair this suite with the focused Dead Pixel Test for locating individual bad pixels and the Screen Bleeding Test for grading backlight bleed on a dark screen.