FREE ONLINE DISPLAY TOOL

Black Screen Test

Check your monitor, laptop, phone or TV for visible pixels, light leakage, uneven black levels and other display issues using a pure black screen.

Start the test ↓

DISPLAY TEST

Black Screen Test

Choose a color, enter fullscreen mode, and inspect your display.

Black

⚡ Ready to test your screen Choose a color below or start the guided test.

Test timer

Timer off

Keyboard: Press F for fullscreen, 1–5 to switch colors, and Esc to leave fullscreen.

QUICK START

How to use the black screen test

A black screen is useful because small display problems can be easier to see against a uniform dark background. Start with the black test, then switch through the other solid colors. You do not need special software or an account.

Open the test on the display you want to check. Use the monitor, laptop, phone or TV that you want to inspect.
Set the display to a comfortable brightness. Start with your normal everyday setting rather than immediately turning brightness all the way up or down.
Enter fullscreen. This removes most distractions and gives you a larger uniform area to inspect.
Check the black screen. Look at the center, edges and corners for unusual bright spots, patches or pixels.
Cycle through white, red, green and blue. A single black screen cannot reveal every type of pixel problem, so the color test is important.
Compare what you see with normal use. A small variation that is only visible in a dark room at extreme brightness may not have the same practical importance as a defect that is obvious during everyday use.

WHAT TO LOOK FOR

What can a black screen test reveal?

This tool helps you visually inspect your display. It cannot confirm a hardware defect by itself, but it can make unusual pixels, light leakage and screen uniformity problems easier to notice.

Dead pixels

A dead pixel may remain dark when the surrounding screen changes to a bright color. Check several colors before deciding that a pixel is defective.

Stuck pixels

A stuck pixel or sub-pixel may remain visible as a particular color while the surrounding image changes. Solid red, green and blue screens are useful for spotting these differences.

Backlight bleed

On LCD displays, light can sometimes be more noticeable near the edges or corners against a black background. Compare the effect at your normal brightness.

IPS glow

Some IPS displays can show a glow that changes as your viewing angle changes. That is different from concentrated light leakage in a fixed location.

Uneven black levels

Large areas of a black screen can make differences in uniformity easier to see, especially in a dim room.

Bright spots

Unexpected bright dots or small illuminated areas may become easier to notice when the rest of the display is completely black.

STEP-BY-STEP

How to test a monitor properly

For a useful test, check the display under conditions that are close to how you normally use it. If you are specifically looking for light leakage, a darker room can make the effect easier to see.

Before you start

Clean visible dust or marks from the screen surface if needed.
Let the display operate normally before judging its appearance.
Start with your usual brightness and contrast settings.
For backlight observations, reduce strong room reflections.
Sit at your normal viewing distance.

During the test

Start with black and inspect the entire screen.
Look carefully at all four corners.
Check the edges and then the center.
Switch to white and look for dark spots.
Switch to red, green and blue.
If you see a suspicious area, view it from your normal position and then from a slightly different angle.

A browser test is a visual inspection aid, not a laboratory measurement or a definitive hardware diagnosis.

UNDERSTAND THE DIFFERENCE

Dead pixel vs stuck pixel

Issue	What you may see	Useful test colors
Dead pixel	A pixel that stays dark when surrounding pixels are displaying another color.	White, red, green and blue
Stuck pixel	A pixel or sub-pixel that stays visible as a particular color while the surrounding screen changes.	Red, green, blue and white
Bright spot	A small area that remains noticeably brighter than the surrounding black field.	Black

If a spot appears on only one color, switch through the other colors before drawing a conclusion. Pixel behavior can look different depending on the panel and the color being displayed.

COMMON CONFUSION

Backlight bleed vs IPS glow

These terms are often used interchangeably online, but they describe different visual effects. Both can become more noticeable when a dark screen is displayed in a dim room.

Backlight bleed

Usually appears as concentrated light leakage around an edge or corner of an LCD panel. It tends to remain in the same physical location.

IPS glow

Can appear as a softer glow on some IPS displays and may change noticeably when you move your viewing position.

If you notice glow around a corner, change your viewing angle slightly. If the appearance changes substantially, it may be more consistent with IPS glow. If a bright area remains concentrated in the same location, it may be worth investigating further. Your display's manufacturer specifications, return policy and warranty terms should be used for the final decision about whether a panel needs replacement.

BY DEVICE

Can I use this black screen test on different devices?

MonitorDesktop monitors are ideal for this test because you can use fullscreen mode and inspect a large uniform area. Check the corners carefully when looking for light leakage.

LaptopOpen the test on the laptop display itself. Avoid judging the panel from an extreme viewing angle because the appearance of some displays can change with angle.

PhoneThe color test works in a mobile browser. Turn up the screen enough to see details comfortably and use the solid colors to inspect individual pixels.

TVYou can open the page on a compatible smart TV browser or display the page from another device. Use your normal viewing distance when deciding whether a visible issue matters.

OLED displayOLED panels produce black differently from traditional LCD panels because their pixels can turn off individually. A pure black screen can therefore be useful for observing black-level behavior and uniformity.

LCD / IPS displayBlack screens can make backlight-related effects and IPS glow easier to notice. Test at normal settings before deciding whether what you see is a problem.

WHEN SHOULD YOU BE CONCERNED?

When should you be concerned?

Not every unusual-looking area means your display is faulty. Room lighting, brightness, viewing angle, panel technology and camera exposure can all change how a black screen looks. If you notice a persistent spot during normal use, test it with several colors, view it from your normal position, and compare the result with the manufacturer's guidance and warranty terms.

EXPLORE MORE

Related display tools

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Black Screen Online

Open a simple pure black fullscreen.

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Black Screen Image

Download or view a pure black image.

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Dead Pixel Test

Check your display with solid colors.

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OLED Black Screen

Learn about black on OLED displays.

FAQ

Black screen test questions

How do I test my screen for dead pixels?

Open the test, use fullscreen mode, and cycle through black, white, red, green and blue. Look for individual pixels that stay dark, bright or the same color while the rest of the screen changes.

What does a black screen test check?

A black screen makes bright pixels, light leakage, uneven black levels and some uniformity issues easier to see. It is especially useful as part of a wider color test rather than as the only test.

Can a black screen test detect backlight bleed?

It can help you visually inspect for bright areas around the edges or corners of an LCD display. The test cannot confirm the cause of what you see, so compare the result at normal brightness and viewing conditions.

How do I check for stuck pixels?

Cycle through red, green, blue, white and black. A pixel that remains visible as a particular color while the surrounding screen changes may be stuck. Test more than one color before drawing a conclusion.

Why does my black screen look gray?

LCD technology normally uses a backlight, so black may not look as deep as it does on an OLED display. Bright room lighting, reflections and display settings can also affect how black appears.

Why does my monitor glow around the corners?

Some LCD displays can show IPS glow or other light leakage around dark areas. Try changing your viewing angle slightly. If the appearance changes strongly with angle, it may be more consistent with IPS glow.

Can I use this test on my phone?

Yes. The test works in a modern mobile browser. Use the solid color buttons and fullscreen mode where supported, and inspect the screen at a comfortable brightness.

Can I use a black screen test on an OLED display?

Yes. OLED displays create black differently from LCD displays because individual pixels can turn off. A black screen can therefore be useful for observing black-level behavior and screen uniformity.

Does a black screen test damage my monitor?

No special hardware operation is required. The page simply displays a solid color in your browser. You should still use normal brightness settings and take regular breaks from prolonged screen viewing.

Is a browser test enough to prove that my monitor is defective?

No. This is a visual inspection tool. If you find a persistent issue, check it under normal conditions and consult the manufacturer's specifications, return policy or warranty information.