Online tool
Run full-screen tests right in your browser to spot dead pixels, backlight bleed, color casts and banding. Pick a color or the grayscale below, then click the preview.
White#FFFFFF
Reported by your browser, for reference only.
On a phone, tap the screen to change the color.
White
White should be even and neutral. A yellow, blue or pink cast, or a duller patch, points to a color shift or uneven brightness.
← → change · F full screen · Esc exit
Step 1: Prepare
Keep the screen on for at least 30 minutes so its temperature settles. Turn off automatic color modes such as Night Light or True Tone, and set the brightness you normally work at.
Step 2: Run a test
Pick a test, go full screen and change the color with the arrow keys. Look from your normal working distance, then move in close to inspect individual pixels.
Step 3: Take note
Write down what you see: dead pixels, backlight bleed, color casts, bands on the grayscale. If you find a problem, get in touch for advice.
Done!
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A few things worth knowing before you test your screen.
No. Checking by eye only tells you whether the screen has an obvious fault. Calibration uses a measuring instrument to find out how far off the screen is and creates an ICC profile to correct it.
A screen needs time to settle in temperature, so color and brightness right after switching on can differ from what you get once it has been running for a while.
Usually a faulty pixel (dead or stuck). Bright dots show up best on black, dark dots on white. Policies for handling them differ by manufacturer and seller, so contact the place you bought it from.
They can come from the panel itself or from display settings. Try the native resolution and a standard cable. If they are still clearly visible, get in touch and we will take a look.
Yes, as long as the browser can open this page. Some devices do not support true full screen, in which case the tester still fills the browser window.
Not sure whether your screen is a good candidate? Get in touch with your display model and setup, and we will advise you directly.
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