Screen edges look darker? How to check the display

The center of your screen looks bright, but the corners or sides seem dim. This can be an image or viewing-angle effect, a display setting, or uneven lighting in the panel itself. A quick comparison can help you tell which is more likely.

Use the Display Test to check solid colors on your screen. The test can show whether the darker edges appear across the display, but it cannot diagnose the panel or measure its backlight directly.

Check whether the screen edges are actually darker

1. Open the Display Test on the screen you want to check, and use its color test to show a uniform color.
2. Look at the screen from your usual seated position, with your eyes roughly centered on the display. Check a light gray or white field, then a medium gray field.
3. Move your head a little to the left and right, then look at the screen straight on again. Note whether the dark area moves or changes as your viewing angle changes.
4. Compare the test with a plain background in another app, and, if possible, another display. Keep the room lighting and screen brightness steady while comparing.

Do not press or rub the screen to see if the dark area changes. Pressure can damage a panel, and it does not provide a reliable diagnosis.

What the result means

The edges look darker only from an angle

The panel's viewing angle may be changing how bright the image appears. Some LCD screens lose brightness or contrast when viewed away from the center. Sit directly in front of the display and check whether the effect becomes less noticeable. If it does, the panel may be behaving normally for its type.

The same area stays dark on every color

If the same edge or corner looks dim on multiple uniform colors, in different apps, and from a centered position, uneven panel lighting is more likely. On an LCD, this can be related to the backlight or the panel layers. OLED screens do not use a backlight, but they can still show uneven brightness or color.

The dark edges appear only in one app or video

The screen may be fine. The image itself could have dark borders, a vignette effect, or a crop that leaves unused areas at the sides. Open another app or a plain color field to check. If the test looks even, inspect the original image, video, or app layout.

The edges change when a display mode changes

Automatic brightness, HDR, local dimming, or a picture preset can affect brightness across the screen. A change after switching a setting does not prove the panel is defective. Compare the same color with those features on and off, and keep a note of which setting changes the result.

How to fix or narrow it down

1. View the display straight on. Center your chair and adjust the screen angle so you face the panel directly. For a laptop, open the lid to a different angle and check whether the edge shading changes.
2. Check whether the content has dark borders. Test a plain color field and compare it with another app. If the dim area is absent in the test, check the source image or video for a vignette, letterboxing, or a dark overlay.
3. Turn off automatic brightness and color changes temporarily. On Windows 11, open Settings › System › Display and check brightness, HDR, and Night light options available for your display. On macOS, open System Settings › Displays and compare with Night Shift, True Tone, or automatic brightness disabled where available. Menu options vary by computer and screen.
4. Check the monitor's picture settings. Use the monitor's physical controls to temporarily select a standard picture preset. Turn off features such as dynamic contrast or local dimming for the comparison, if your monitor has them. Restore your preferred settings afterward.
5. Check the screen protector or case. On a phone or tablet, remove a case that overlaps the display edge and inspect the screen protector for dark borders, lifting, or damage. On a phone, compare with automatic brightness off in Settings › Display on Android, or Settings › Accessibility › Display & Text Size on iPhone. Names and locations vary by device.
6. Compare another input or device. If you are using an external monitor, open the test from another computer or connect a different source. If the same edge stays dark with different sources, the display itself is a stronger suspect.

When it may be a panel problem

Uneven lighting is more likely to be a hardware issue when the same edge stays dim on plain colors, across apps and inputs, with the display viewed straight on and automatic adjustments disabled. Check whether the problem is new or getting worse, and take a photo from directly in front of the screen with a uniform gray image visible. A camera can exaggerate brightness differences, so use the photo as a record rather than proof of exact severity.

If the screen is new or still under warranty, compare the result with the maker's return or defect policy before attempting a repair. A laptop or monitor panel may need service or replacement. If a phone screen became uneven after a drop, bending, or pressure, arrange a repair inspection rather than trying to massage the dark area away.

Why a gray screen can reveal more

A bright white image can make subtle differences hard to notice, while a dark image can hide them. Medium gray gives your eyes a useful middle ground for checking whether brightness changes near the edges. For a fuller check of screen uniformity, see how to check a display for uneven white balance.

A browser test can show a pattern on the screen, but it cannot tell whether the cause is the panel, its backlight, or a display setting. Use it to make a consistent comparison before deciding what to adjust or report.