Interactive diagnostic

Screen & dead pixel test

Inspect your display with controlled solid colors. Nothing is captured, uploaded, or analyzed remotely.

Processed locally in this browser

Visual inspection

Inspect pixels and tone transitions

The test shows six solid colors and one grayscale gradient. You review mismatched dots and pronounced tone bands. DeviceTriage cannot automatically detect physical display defects.

Display reported by browser: Reading display information…
Data handling: No image or screen content is captured

Browser report

Color and dynamic range

These signals show how the browser classifies the current display path; they do not measure the panel model, calibration, or actual HDR brightness.

Color gamut: Unknown
Dynamic range: Unknown

Only the measurement and review summary stays in this browser for 7 days for Device Check and JSON reports. No photos, video, audio or screenshots are stored. Denied permission and unfinished tests are not faults. Visual and listening reviews are labeled as user reports.

Test guide

What this test proves—and what it cannot

The screen test fills the viewport with controlled solid colors and neutral tones so you can visually inspect pixels, brightness uniformity, tint, and image persistence. It is an observation aid: the browser cannot electrically read the panel or confirm a manufacturing defect.

Last reviewed: 2026-09-01

Signals measured

User-visible pixels that remain dark, bright, or the wrong color
Uneven brightness, color tint, banding, or clouding across solid fields
Possible temporary image persistence after a static image
Screen and viewport dimensions reported separately from physical panel size
Browser-reported color gamut and dynamic-range classification

How the test works

Full-screen color fields reduce page detail that can hide a suspicious pixel.
Black, white, red, green, blue, and gray reveal different pixel and uniformity behavior.
The user confirms observations; no image or screen capture is taken.
Normal brightness and a clean screen reduce false observations.
CSS media queries report whether the current display path is classified as sRGB, Display P3, standard, or high dynamic range.

Interpreting the results

SignalWhat it meansNext step

All fields look uniformNo obvious issue was visible under this quick inspection.Retest only under the conditions where the symptom normally appears.

One fixed dotIt may be dust, a stuck subpixel, dead pixel, scaling artifact, or overlay.Clean safely, compare a screenshot on another display, and test multiple colors.

Large uneven areaViewing angle, backlight, panel pressure, HDR, dimming, or panel behavior may contribute.Return to normal angle and settings; compare another input before service.

Measurement limits

Browser colors pass through the operating system, browser, color profile, HDR, and panel processing.
A visual check cannot calibrate color accuracy or measure luminance.
Touch glass dust and screen protectors can resemble pixel defects.

Missing or privacy-reduced detail is not scored as a fault by itself.

Questions about this test

Can a website repair a stuck or dead pixel?

No repair is guaranteed. Rapid color changes can sometimes alter temporary persistence, but physical pixel defects require warranty or repair evaluation.

How do I tell a screen defect from a graphics artifact?

Take a screenshot and view it on another device. If the mark appears in the screenshot, investigate software or graphics; if it stays at one physical point, inspect the panel path.