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TextArray1.117.0
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Screen test

Fill your screen with solid colours and a gradient to spot dead pixels, stuck pixels, backlight bleed and banding.

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Screen test
This screen test fills your whole display with one flat colour at a time so that defects have nowhere to hide. Open a pattern in full screen, look closely at the entire panel, then move on. Black, white, red, green, blue and mid grey each show a different kind of fault, and a black-to-white gradient shows banding.
Read the results by pattern. On black, a pixel that stays lit is stuck, and light creeping in at the edges or corners is backlight bleed. On white, a dark dot is a dead pixel and a smudge is dirt or pressure damage. Red, green and blue isolate single sub-pixels, so a pixel that is always on in one colour shows up clearly. Grey reveals uneven brightness and a colour tint, and the gradient should look smooth rather than stepped.
Click, press Space or use the arrow keys to change pattern, and press Esc to leave. The page never cycles or flashes on its own, so it is safe for people sensitive to flicker. The report lists the patterns you have viewed, the ones that remain and what to look for in each. You can also paste a log by hand to get the same report.
The test runs entirely in your browser and nothing is sent anywhere. A browser cannot measure a defect for you: you judge the panel by eye, in a dim room and from a normal distance, and some faults only show at certain brightness settings. On phones without a fullscreen mode the pattern fills the viewport instead, and browser toolbars may stay partly visible.
FAQ
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays black on every colour, so it is easiest to see on white. A stuck pixel is always lit in one colour, so it stands out on black. Stuck pixels can sometimes recover; dead ones rarely do.
How do I tell backlight bleed from a normal dark screen?
Show the black pattern in a dim room and look at the edges and corners. Pale patches of light that do not fade are backlight bleed. A little is common on LCD panels, while bright clouds are worth a warranty claim.
Is it safe to use with photosensitivity?
The patterns change only when you click or press a key. Nothing flashes or cycles by itself, but a full white or red screen is still bright, so lower your brightness first if it bothers you.
Is anything uploaded or recorded anywhere?
No. The test runs in your browser, the list of viewed patterns stays in memory, and nothing is sent or stored.