Pixel Grid Test
Press Full Screen on the fine checkerboard. At native resolution it blends into uniform grey — if you see grid lines, moiré, or colour fringing instead, your display isn’t rendering pixel-sharp, and this test shows why.
New to this? Here’s the plain-English version.
What this test is
A fine 1-pixel checkerboard that checks your screen is running at its native resolution and rendering pixel-sharp.
How it helps you
It confirms you’re getting the crispness the panel is capable of — and catches blurry scaling or sub-pixel issues that make text look fuzzy.
What we’re checking
Whether each software pixel maps cleanly to a physical pixel (sharp) or the image is being interpolated (soft), plus any colour fringing.
This pattern should appear as a uniform, 50% gray field. Any banding, moiré patterns, or color variations can indicate scaling issues or improper monitor setup.
Press F11 or Full Screen · ← → patterns · Esc to exit
What the Pixel Grid Test Checks
At native resolution, each software pixel maps exactly to one physical pixel — the image is as sharp as the panel allows. At non-native resolutions the display has to interpolate, which softens the image or overlays a faint pixel-grid effect. This test also reveals the sub-pixel layout (usually RGB stripe) and catches persistent sub-pixel irregularities that aren’t full dead pixels.
How to Use the Test
- 1Set native resolution. Confirm your OS display setting matches the panel’s native resolution before testing — non-native resolutions invalidate the result.
- 2Display the fine grid. The 1-pixel checkerboard should look like uniform grey at native resolution. Visible lines, moiré, or uneven brightness signals a rendering issue.
- 3Check the corners. Look closely at each corner — sharpness should be consistent. Corner softness suggests panel bow or edge pixel-pitch variance.
- 4Look for colour fringing. A 1-pixel black/white pattern should render pure grey. Red, green, or blue fringing indicates a sub-pixel rendering or layout issue.
What to Look For
| Observation | Meaning |
|---|---|
| Uniform grey on fine checkerboard | Native resolution confirmed, rendering correct |
| Visible black grid lines | Non-native resolution or scaling active |
| Moiré (wavy interference) | Panel pixel pitch interacting with content frequency |
| Colour fringing on fine lines | Sub-pixel rendering misconfigured or a sub-pixel defect |
| Corners visibly softer | Panel mounting stress or manufacturing tolerance |
| Isolated coloured pixels | Sub-pixel defect (partial pixel failure) |
Scaling and HiDPI
On HiDPI / Retina displays the OS renders at 2× or more — four physical pixels per logical pixel. At 200% scaling this test confirms that 2× mapping is clean; mismatched or fractional scaling ratios (125%, 150%) produce visible softness or fringing because they require interpolation. Where you can, stick to integer scaling for the sharpest result.
Seeing coloured edges on fine lines rather than blur? That is a sub-pixel alignment issue — the convergence test isolates it. And a persistent coloured dot that ignores the pattern is a sub-pixel defect — confirm it with the dead pixel test.
Pixel Grid FAQ
What resolution should I run the test at?+
What does a sub-pixel defect look like?+
Why does the fine grid look grey instead of black and white?+
Does scaling affect pixel clarity?+
Why does my text look slightly coloured on fine edges?+
What is the difference between this and a dead pixel test?+
Why are my screen corners softer than the centre?+
Related Monitor Tests
Checking a whole new panel?
Run the dead pixel test and browse the full monitor test suite.