Online Screen Test
It works out of the box on Macs, Windows computers, iPhones, iPads, and Android devices. The test pattern displays full-screen in the browser, without the need to install an app or upload an image.
Dead pixels, bright spots, or dust on the screen surface?
Dead pixels usually remain black on a bright background such as white; bright or stuck pixels are more obvious on a black background and may always appear red, green, blue or white. After discovering a suspicious location, change several colors to observe the same point.
Wipe the screen clean before checking, and also pay attention to scratches and bubbles on the protective film. Dust, scratches, and reflections change with cleaning, lighting, or viewing angles; pixel anomalies are often fixed in the same location.
How to look at light leakage, color cast and color banding respectively
LCD screens can check for edge light leakage in darker environments with pure black patterns. Some panels will naturally appear white when viewed from the side, so you should focus on the central viewing angle for daily use, and don't just rely on cell phone photos or extreme angles to judge.
The medium gray background is suitable for looking for partial color casts, dirty screens and slight afterimages, and the grayscale gradient is suitable for looking for sudden jumps and color bands. Physical screen defects will not appear in screenshots; if the exception is still visible when the screenshot is moved to another screen, the problem is more likely to come from the software, driver, or graphics output.
Fixed brightness and display settings
Adjust the brightness to a higher level for daily use, and temporarily turn off auto-brightness, night mode, eye protection mode, and adaptive color temperature. You can reduce the ambient light when checking for light leaks, but you don't have to make the room completely dark.
Start by looking at it from the front, then slightly change the angle. It is recommended to watch it once on mobile phones and tablets in horizontal screen and vertical screen. Some panels are inherently white when viewed from the side, and cannot be judged based on extreme angles alone.
A suspicious point, at least two different background checks
White is suitable for looking for black spots, black is suitable for looking for bright spots and stuck pixels; gray is suitable for looking for color casts, dirty screens and slight afterimages; grid is suitable for looking for whether the edges are straight and whether the picture is stretched.
After finding an abnormality, remember the location and switch between two or three patterns. If the marks move with wiping, reflections, or viewing angles, the problem usually isn't with the pixels themselves.
FAQ
Can this find every screen problem?
cannot. It is suitable for finding dead pixels, bright spots, color casts, light leaks and color bands that are visible to the naked eye. Occasional flickering, touch failure, wiring problems, and abnormalities that only occur under high load need to be tested separately.
Why does fullscreen matter?
Full screen hides the browser toolbar and allows the test color to cover a larger area. Dead pixels, shiny corners and partial color casts will be easier to see.
How to distinguish dust and bad pixels?
Wipe the screen clean first, then switch between white, black, red, green and blue. Bad pixels are fixed at the same pixel location; dust, scratches, and reflections often change with wiping, lighting, or viewing angles.
Is the shiny edge of the black screen necessarily a light leak?
uncertain. When the IPS screen is viewed from the side, the corners may naturally appear white; reflections and the automatic exposure of mobile phone photos will also make the bright spots more serious. Please observe directly under normal use angle.