What did you notice?
Choose the closest visible symptom. You can change the selection before opening a test.
Compare the fixed point on white, red, green, blue, and grey fields.
Choose by symptom, not by guesswork
This screen test hub matches a visible symptom with a focused browser workflow. Start with the smallest useful check, compare more than one field, and treat the result as a visual observation rather than an electronic measurement of the panel.
Two scales of evidence
The size and behavior of the mark determine which screen test is most useful.
A single fixed coordinate that stays dark, bright, or colored belongs in the dead-pixel or stuck-subpixel workflow. Compare that exact point on black, white, RGB, CMY, and grey fields. A point that moves with a reflection or changes after coating-safe cleaning is less consistent with a physical pixel defect.
A corner glow, bright edge, broad tint, vertical band, cloud, or dirty-screen effect is larger than one pixel. Neutral fields and a consistent viewing position help separate luminance or tint uniformity from angle-dependent panel behavior, backlight effects, and image processing.
Focused tools with different jobs
Pure black can expose a bright or stuck point. Low grey levels add shadow-field context for LCD glow, OLED near-black behavior, and dark-scene irregularities without pretending to measure physical black luminance.
White makes dark points and some surface specks easier to see. Bright neutral steps and optional zones also help compare tint or brightness across the panel at a comfortable device brightness.
RGB and CMY fields support channel comparisons; custom colors recreate a background where a mark was first noticed. Split fields and a simple ramp reveal obvious visual differences, not calibrated color accuracy.
A short first-day workflow
Use normal settings first. Extreme conditions can make minor effects look more important than they are in use.
What the browser contributes
Normal images contain edges, texture, compression, and many colors. A browser screen test replaces that visual clutter with controlled CSS fields or simple patterns. Your eyes can then compare neighboring pixels or larger panel regions under repeatable conditions.
The requested color passes through the browser, operating system, GPU, color profile, cable or internal display link, and the panel’s own processing. That chain is exactly why this screen tester is useful for visible inspection but cannot report laboratory values. A colorimeter or imaging photometer is required to quantify white point, gamut, Delta E, luminance, contrast, or zone-to-zone deviation.
Continue by observation