Screen Display Diagnostic Test
Full monitor calibration and diagnostic test suite. Inspect color bars, 10-bit gradient smoothness, contrast ratio steps, subpixel text clarity, and geometric alignment.
How to Use This Tool
- Click "Enter Fullscreen Test" to view test patterns without browser toolbars.
- Switch between the 5 diagnostic patterns:
- Color Bars: Check primary and secondary color purity.
- Gradient: Look for smooth grayscale transitions without harsh vertical bands.
- Contrast: Ensure you can distinguish between dark grays and pure black, as well as light grays and pure white.
- Geometry: Confirm grid lines are straight and circles are perfectly round.
- Subpixel Text: Check font clarity at tiny and large sizes.
- Press the ESC key to return to normal view.
Fixing Color Banding in Gradients
If the smooth black-to-white gradient appears as distinct, blocky vertical stripes instead of a continuous blend, your GPU dynamic range may be set incorrectly. In the NVIDIA Control Panel, AMD Software, or Intel Graphics Command Center, ensure Output Dynamic Range is set to "Full (0-255)" rather than "Limited (16-235)".
Calibrating Brightness & Contrast
Using the Contrast pattern, adjust your monitor's physical Brightness so that the 1% and 2% dark gray blocks are barely visible against the pure black background. Then adjust Contrast so the 98% and 99% light gray blocks remain distinguishable from pure white.
Device Pixel Ratio (DPR) & Scaling
The Device Pixel Ratio (DPR) metric shows your operating system's display scaling. A DPR of 1.0 means standard native scaling (100%). High-DPI screens (like 4K monitors or Apple Retina displays running at 150% or 200% scale) display a DPR of 1.5 or 2.0, delivering razor-sharp text without tiny, unreadable UI elements.