Let the display sleep
A still image left up for hours is a common way a ghost starts. Use the system sleep setting. Sleeping the panel does not remove a mark that is already there.
Exact fields, on this device
Open a white field
Fill the panel with pure white, or pick another solid colour from the list. You do the looking. This page does not mark a fault, and it does not send what you see anywhere.
White · #FFFFFF
Off by default. When it is on, the full-screen field walks through white, black, red, green, blue and grey, about 5 seconds each. It does not flash, and it does not fix pixels.
Visual inspection — this tool does not automatically detect defects.
Named fields
White, then black, then red, green and blue. You move each field yourself.
The cycle is slow on purpose. It is not a flashing repair mode, and it does not fix pixels.
Signal greys for uniformity. Percent means a share of 255, not measured brightness.
Colour screens
Each block is the real test colour. Open it to use that field on its own page.
Four fields, in this order
One flat colour hides what another shows. These four are enough for a first pass.
-
1
White
Begin here. Dark specks, a slight tint and surface dust are easier to see on a blank white field.
-
2
Black
Go here next. A point that stays lit, and light around the edges in a dim room, stand out when the field is black.
-
3
Red, green and blue
A pixel is three parts. If a mark changes on only one of these, write down which colour.
-
4
Grey
Finish on a mid grey. Broad clouds and bands that white or black can hide tend to show here.
Treat the panel gently while you look
Save full brightness for a short look
Everyday use is kinder below the maximum. Turn it up only while you are inspecting, then bring it back down.
Do not press the glass
A finger or a stylus can leave a mark. Hold the device by the frame.
Use a dry microfibre cloth
That is enough for dust. Do not spray liquid onto the panel. If a slightly damp cloth is allowed, dampen it away from the glass.
If you notice a mark
These are ways to describe what you see, and a sensible next step. This site does not repair a panel.
Dead-looking pixel
Cause
A sharp point that stays dark on bright fields.
Next step
Note which colours show it, and whether a dry wipe moves it. Sellers set their own return rules. Nothing here guarantees a replacement.
Stuck-looking pixel
Cause
A point that stays lit, often easiest to see on black.
Next step
Compare it on red, green and blue. Do not rub or press the spot, and do not run a flashing routine. Write down what you see and read the maker’s warranty terms.
Backlight bleed
Cause
Light near the edges of an LCD, clearest in a dark room.
Next step
Sit straight on, then shift your head. Glow that moves with you is a different observation from a corner that stays bright. If it bothers you in normal light, ask the seller while a return window is still open.
Uneven brightness or a tint
Cause
A broad patch or a colour cast on a flat grey.
Next step
Look in ordinary light, sitting centred. A cast that fades after the panel has been on for a while may be the backlight settling. If it stays, the warranty desk is the place to ask. This page cannot calibrate the display.
OLED image retention
Cause
A faint ghost of something that stayed on screen, or a mark that does not fade.
Next step
Lower the brightness and avoid leaving one image up. A ghost that fades is often temporary. A mark that remains can be burn-in. This site does not undo either.
Dust and smudges
Cause
Something on the surface from ordinary handling.
Next step
Wipe gently with a dry microfibre cloth. Do not spray the glass. If the mark does not move, it may be under the surface rather than on it.
With JavaScript, this line shows the viewport, pixel ratio and fullscreen support reported by the browser. Those figures are not a measurement of the panel.
Where you are looking
Monitor or laptop
Use ordinary light for colours and greys. Dim the room only for the black field. On a laptop, the angle of the lid changes IPS glow, so check at the angle you actually use.
Phone or TV
If the browser will not enter fullscreen, the colour still fills this view. System bars may cover the edges. On a TV, use Previous and Next. A PNG on a USB stick is the alternative when the browser cannot fill the panel.
Private by default
Your data stays here
The test runs in this browser. Notes are saved only if you ask, and only on this device. This build does not upload findings, and it does not include an advertising script.
- No account
- No camera
- No result upload
- PNG patterns
- Privacy notes
What this cannot measure
Browser cadence is not panel response time. A hex colour is not a colour-accuracy report. Brightness in nits needs a meter. Read the method.
- Not brightness in nits
- Not colour accuracy
- Not response time
- Not a pass certificate
Frequently asked questions
Is a very bright white field hard to look at?
It can feel strong. You do not have to set the panel to its highest brightness. Look only as long as is comfortable, then leave the field. This page cannot change the display’s own brightness control.
If my computer is frozen on white, will this page clear it?
No. A test field is a page you choose to open. If the machine is already stuck on white before a browser will load, this site cannot reach it or repair the software.
Does it work on a phone, a tablet, a monitor and a TV?
Yes, in the device’s browser. Phones often refuse fullscreen; the control bar says so and the colour stays the same. A television is easier with the on-screen buttons, or with a PNG from the downloads page.
How do I leave fullscreen?
Press Esc, or Exit on the control bar. On a phone, tap the field once if the buttons are hidden, then choose Exit.