Monitor Geometry Test
Press Full Screen on the grid and check that every horizontal and vertical line stays perfectly straight across the whole panel. Bowing, tilt, or stretching points to a distortion — usually a settings issue, occasionally a hardware one.
New to this? Here’s the plain-English version.
What this test is
A grid of straight lines that checks whether your screen shows them truly straight — not bowed, tilted, or stretched.
How it helps you
It matters for spreadsheets, CAD, and design where straight lines must be straight — and it catches wrong-aspect-ratio settings.
What we’re checking
Whether horizontal and vertical lines stay straight across the whole panel, or bow, tilt, or warp at the edges.
Check for straight and parallel lines. Any curvature may indicate distortion.
Examine the grid lines. They should be perfectly straight and evenly spaced, both horizontally and vertically. Any bowing or warping can indicate a geometry problem with the monitor.
Press F11 or Full Screen · ← → patterns · Esc to exit
What Geometry Testing Checks
Geometry testing checks whether straight lines render as visually straight across the full panel and the image is undistorted and correctly proportioned. On modern flat LCDs this is uncommon but can come from the panel circuitry, the signal pipeline, or mounting stress. On curved monitors the curvature is intentional — here you’re checking for unintended distortion within the curve, not the curve itself.
How to Use the Test
- 1Go fullscreen on the grid. Press Full Screen and bring up the grid or cross-hatch pattern.
- 2Check horizontal lines. Lines at the top, middle, and bottom should all be perfectly straight — any bow or wave is a geometry defect.
- 3Check vertical lines. Repeat down the left, centre, and right. Outward bow is barrel distortion; inward bow is pincushion.
- 4Check the corners. Look for compression, stretching, or warp at the corners — less common on LCD than CRT but possible.
Geometry Defect Types
| Defect | Appearance |
|---|---|
| Barrel distortion | Lines bow outward — convex shape |
| Pincushion distortion | Lines bow inward — concave shape |
| Trapezoid distortion | Image is wider at the top or bottom |
| Tilt | The entire image is rotated slightly |
| Corner warp | Corners pulled up or down |
What Causes LCD Geometry Issues
Because LCD and OLED pixels sit at fixed physical positions, most apparent distortion is a settings problem rather than a hardware fault. Rule these out first:
Signal processing
The GPU or display scaler distorting the image in the pipeline.
Incorrect aspect ratio
4:3 content stretched to 16:9 or vice versa — check display scaling settings.
Panel mounting stress
Mechanical stress from the frame warping the panel substrate in severe cases.
Curved-panel anomalies
Unintended distortion within a curved panel’s curve radius.
Confirm the correct native resolution and aspect ratio before assessing hardware — verify sharpness at native resolution with the pixel grid test. If lines are straight but edges show colour, that’s a convergence issue instead.
Geometry FAQ
Why do straight lines look curved on my monitor?+
Can I correct geometry distortion in software?+
Do curved monitors have geometry issues?+
Is geometry testing relevant for gaming?+
Why is geometry distortion rare on modern monitors?+
My image is slightly stretched — is that a geometry defect?+
How do I check geometry on an ultrawide?+
Related Monitor Tests
Checking a whole new panel?
Run the dead pixel test and browse the full monitor test suite.