How to use the monitor test
A monitor test fills your screen with test patterns so you can see defects and setting problems with your own eyes. The guided check takes about 3 minutes.
- Clean the screen. Dust and smudges look like defects on white. Wipe the panel with a dry microfiber cloth.
- Use your normal brightness. Pick the level you usually work at, and turn off Night Light, True Tone and blue-light filters.
- Press Start guided check. The test goes full screen. Press Esc at any time to stop.
- Look at each screen for about 20 seconds, then answer the question on the card. Press → to see the next screen of a step.
- Read the verdict. Each answer comes with what it means and what to do next. Copy the report if you need it for a return or warranty claim.
- Browse the patterns to look at any of the 22 patterns again, or tap a pattern above to open it directly.
Which monitor test do I need?
Start with the guided check above for a general check of a new or used screen. If you already know the symptom, use this table to open the focused test that confirms it. Focused tests take 1 to 5 minutes and work on any monitor, laptop, TV or phone. Each one explains what it can and can’t detect, and what to do next.
| What you see | Test to use |
|---|---|
| A dark dot that stays black on every color | Dead Pixel Test |
| A red, green, blue or white dot that never changes | Stuck Pixel Fixer |
| Light leaking at the edges in dark scenes | Backlight Bleed Test |
| Games don't feel as smooth as a 144 Hz monitor should | Refresh Rate Test |
| Trails or halos behind moving objects | Monitor Ghosting Test |
| A general check of a new or used screen | Monitor test (this page) |
The monitor test patterns, one by one
The 22 patterns are grouped by what they reveal. You can browse them in any order, and keys 1 to 9 jump to each group.
| Pattern | What to look for | Sign of a problem |
|---|---|---|
| Solid colors (white, black, red, green, blue, cyan, magenta, yellow, gray) | Every pixel changes color | A dot that stays dark, bright or one color |
| 10% and 25% gray | An even tone from edge to edge | Clouds, bright corners or dirty-looking patches |
| Gray and RGB gradients | A smooth ramp | Visible steps (banding) or color shifts |
| 32 gray steps | Every bar looks different from its neighbors | Neighboring bars that merge |
| Color bars and saturation steps | Bright, distinct colors | Steps that merge or colors that bleed |
| Black level (1 to 24) | Squares from 1 to 4 upward | Nothing visible below 17 |
| White level (231 to 254) | Squares up to 250 or more | Nothing visible above 235 |
| Gamma | The 2.2 patch blends into the stripes | A different patch blends in |
| Text and pixel grid | Crisp text and an even gray checkerboard | Blur, color fringes or stripes |
| Geometry | A border on all 4 edges and round circles | Missing edges or oval circles |
The black and white level squares also reveal the RGB range. A PC sends either full range (0 to 255) or limited range (16 to 235). When the PC and the display disagree, the darkest 16 levels all look black and the brightest 20 all look white. That’s why “nothing below 17” points to a range mismatch, not a bad panel.
These are visual checks. They show problems you can see, but they don’t calibrate your screen.
How the monitor test works (and its limits)
The patterns are drawn in your browser at your screen’s real pixel size, so a 1-pixel line is one physical pixel when zoom is 100%. There’s no monitor test software to download, and nothing is uploaded.
A browser can’t measure everything. It can’t read brightness in nits, color accuracy (Delta E) or response time in milliseconds. Those need a colorimeter or lab equipment. The refresh rate shown above the patterns is a quick reading from your browser, not a lab measurement; the refresh rate test measures it in detail.
Your eyes and your room matter too. Viewing angle, room light and reflections change what you see, so look straight at the screen, and dim the room for the dark patterns. If a pattern looks wrong, clean the screen, check your settings and run it again. A defect that stays in the same place on every pattern is in the panel.
Screen color test: what colors can and can’t tell you
A screen color test shows solid colors, color bars, saturation steps and gradients. It reveals tints, clipping and banding: colors that look wrong next to each other on the same screen.
What a monitor color test can’t do is prove that colors are accurate. Your eyes adapt to the white point within minutes, so every screen looks right on its own. Comparing two screens side by side shows a difference, but not which one is correct.
Settings change colors on purpose. Night Light, True Tone, vivid picture modes and wide-gamut modes all shift colors. Turn them off before you judge colors. For accuracy numbers, use a colorimeter with calibration software.
Fixing common problems the monitor test finds
Black or white level squares missing (RGB range). Set the PC and the display to the same range. In NVIDIA Control Panel, open Change resolution and set Output dynamic range to Full. In AMD Software, set Pixel Format to RGB 4:4:4 Pixel Format PC Standard (Full RGB). Intel Graphics Command Center calls it Quantization Range and shows it only on a native HDMI port, not through an adapter. On a TV, match the black level: Samsung calls it HDMI Black Level, and LG calls it Black Level.
Dark details lost (crushed blacks). Raise brightness or the black level setting one step at a time, or try another picture mode such as Standard or sRGB.
Border cut off (overscan). TVs often crop the edges. Turn on Just Scan (LG) or Fit to Screen (Samsung), or set the picture size to 1:1.
Blurry text. Use your screen’s native resolution, pick the recommended display scaling in Windows, and reset browser zoom with Ctrl+0.
Gamma looks off. Choose a gamma of 2.2 in the monitor menu, or switch to the sRGB picture mode.
Dots, lines or glow at the edges. These are panel defects. Check your return window first, because a return is faster than a warranty claim. The dead pixel test confirms dots, and the backlight bleed test confirms glow at the edges.
Screen test on a laptop, phone or TV
Laptop screen test
Plug the laptop in. Battery saver modes can dim the screen and lower the refresh rate. Turn off adaptive brightness so the backlight stays steady during the test.
Mobile display test on a phone or tablet
Turn the phone to landscape and turn off auto-brightness. iPhone Safari can’t show web pages in true full screen, so the test fills the whole window instead. Tap the right side of the screen to go forward and the left side to go back.
TV
Open this page in the TV’s browser, or connect a laptop over HDMI. Use the TV’s PC or Game mode to switch off processing that changes the image. Then check the geometry pattern for overscan.