How to use the Screen Test
- Clean the screen, then press Start full-screen test.
- Click, tap or press → to go to the next color; ← goes back. Press Esc to exit.
- On each color, scan the screen slowly for dots that stay black, white or the wrong color.
Dead pixels vs. stuck pixels
A dead pixel stays black on every color — it is not getting power. It is most visible on the white screen. A stuck pixel shows one color all the time (often red, green or blue) and is most visible on black. Stuck pixels can sometimes be revived; dead pixels usually cannot.
Backlight bleed and uniformity
On the black screen in a dark room, light leaking around the edges is backlight bleed, common on LCD panels. On the gray screen, look for darker or tinted patches — that is uneven uniformity. Check new monitors within the return window: many manufacturers have a dead-pixel policy.
Frequently asked questions
Does this screen test work on phones and TVs?
Yes. Any device with a browser can run it. On phones, tap to change colors.
How can I fix a stuck pixel?
Rapidly flashing colors over the area for several minutes sometimes frees a stuck pixel. Gentle pressure with a soft cloth is another method, used at your own risk.
Why does the test need full screen?
So browser bars and your wallpaper do not hide any part of the panel.