DISPLAY DIAGNOSTIC TOOL

Screen Uniformity Test

Check whether your monitor, laptop, phone or TV displays the same brightness and color across the entire screen.

Ready. Dim the room for dark-screen checks.

01 · TEST PATTERNS

Choose a uniform color

Solid colors make uneven brightness, tinting, clouding and darker or brighter areas easier to notice.

Space/→ next · ← previous · F fullscreen · Esc exit

02 · HOW TO TEST

How to test screen uniformity

Clean the display and remove reflections.
Set the display to a normal viewing mode and comfortable brightness.
Start with 50% gray, then compare dark gray, white and primary colors.
Look across the center, edges and all four corners for areas that are noticeably brighter, darker or tinted.
Move your head slightly to confirm that the effect is on the panel rather than caused by viewing angle.
Repeat suspicious patterns at normal viewing distance. A defect that is invisible during ordinary use may not matter practically.

Important: A browser cannot produce a laboratory uniformity score. Professional systems can use calibrated cameras or colorimeters and controlled conditions; this tool is for visual inspection.

03 · WHAT TO LOOK FOR

Common screen uniformity problems

Brightness variation

One region can appear brighter or darker than another, especially on a large uniform field.

Color tint

A section may look warmer, cooler, greener, pinker or otherwise different from the rest of the same color.

Clouding / DSE

Large patches or dirty-looking areas may become visible on gray or dark screens. Gray uniformity is commonly used to inspect these effects.

Vignetting

The edges or corners can look darker than the center, or the center can look brighter than the surrounding area.

04 · TEST COLORS

Why we use several shades

Pattern	Useful for
5% gray	Very dark uniformity and subtle near-black variation
10% gray	Dark-scene clouding and tint
25% gray	Low-level brightness variation
50% gray	General gray uniformity and dirty-screen effects
75% gray	Mid-to-bright uniformity
White	Bright-field brightness and color consistency
Red / Green / Blue	Channel-specific color variation and tint

05 · LCD & OLED

Does uniformity testing work on OLED?

Yes. Uniformity can matter on both LCD and OLED, although the underlying causes differ. LCD panels can show backlight-related variation, while OLED panels can show their own luminance or color uniformity differences.

For OLED displays, low-level gray patterns can be particularly useful when checking dark-scene uniformity. Do not confuse a visual browser test with a measured panel score: professional measurement uses controlled equipment and defined procedures.

06 · WHEN IT MATTERS

When is poor uniformity noticeable?

Uniformity problems are most distracting when large areas of the image have similar colors or brightness. They can become noticeable on websites, documents, skies, sports fields, panning shots, dark movie scenes and other large flat areas.

Don't judge a panel solely from one extreme test image. Check it under the brightness and viewing conditions you normally use.

07 · FAQ

Screen uniformity test FAQ

What is screen uniformity?

It describes how consistently a display reproduces the same brightness and color across different areas of its panel.

What gray should I use for a uniformity test?

There is no single best gray for every problem. 5–10% gray is useful for dark uniformity, while 50% gray is commonly used for broader gray-uniformity inspection.

Is screen uniformity the same as backlight bleed?

No. Backlight bleed is one possible issue. Uniformity is broader and can include brightness variation, color tint, clouding, dirty-screen effects and vignetting.

Can this tool measure Delta E or standard deviation?

No. It is a visual browser test. Objective measurements require calibrated equipment and controlled conditions.

Can I test a phone or TV?

Yes. Any device with a modern browser can display the test patterns. Fullscreen is recommended.

MORE DISPLAY TESTS

Keep checking your display

Black Screen → Dead Pixels → Backlight Bleed → OLED Test →