Dead Pixel Simulator
See what dead, stuck, bright and subpixel defects can look like before checking your own screen — at real size, at subpixel zoom, and on any background.
Jump to another test
See the three common pixel defects
Tap a preset. The preview updates immediately.
Advanced simulator settings
Full screen puts the simulated defect on your actual panel at true pixel size — the honest answer to "would I even notice one?"
Subpixel zoom
Each block is one pixel, split into its red, green and blue stripes. This is what a microscope shows and why a "dead" pixel and a "dead green subpixel" are completely different faults — one goes black, the other shifts the color of that single dot.
Dead vs stuck vs bright pixel
The same three defects, side by side. Switch the background and watch which ones change — that is the single most useful thing to know when you are trying to identify a dot on your own screen.
Dead / dark pixel
Every subpixel is off
Stuck red subpixel
The red subpixel is stuck on
Bright pixel
Every subpixel is stuck on
Each block is one pixel, split into its red, green and blue stripes. Switch the background and watch which dots change — that is the observation that tells the defect types apart on a real screen.
| Type | What you see | Changes with the background? | Worth trying to fix? |
|---|---|---|---|
| Dead / dark pixel | A black dot, invisible on black | No — stays dark | No. Software cannot power it back on |
| Stuck subpixel | A red, green or blue dot | Partly — hides on its own color | Yes, color cycling sometimes helps |
| Bright / hot pixel | A white dot, obvious on black | No — stays bright | Sometimes. Try cycling, then claim |
| Dead subpixel | A faintly tinted dot | Yes — follows the background | No, but it is also the least visible |
Find the Dead Pixel
One black pixel is hidden somewhere on your screen. How fast can you find it? Good practice for the habit that actually matters — sweeping the panel in rows instead of letting your eyes wander.
Change difficulty
From simulation to the real thing
The simulator teaches the two habits that make real inspections reliable: scan systematically — sweep the screen in rows rather than letting your eyes wander — and check every background color, because each defect type is only visible against the right backdrop. A black dead pixel vanishes on a black background; a green stuck subpixel vanishes on green.
When you can consistently find the 1 px defects here, you are ready to run the real dead pixel test on a new monitor, a repaired laptop or that suspiciously cheap used phone. And remember the difference matters: colored dots can sometimes be released, black dots cannot.
Common questions
What does a dead pixel look like?
A dead pixel is a black dot that stays black on white, red, green and blue backgrounds. On a typical desktop monitor a single pixel is roughly 0.25 mm across, so it looks like a speck of dust that will not wipe away. It is invisible on a black background, which is why a proper test cycles through several colors.
What does a stuck pixel look like?
A stuck pixel shows as a small red, green, blue, cyan, magenta or yellow dot, most obvious on a black background. Because one or more subpixels are frozen on, the dot keeps its color while the rest of the screen changes — that behaviour is the giveaway.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel receives no power, so it stays dark no matter what the screen displays and software cannot revive it. A stuck pixel has one or more subpixels frozen in the on state, so it glows in a fixed color — and rapid color cycling sometimes releases it. Dark dots are also treated more leniently than bright dots by most warranty policies.
How big is one pixel really?
On a 27-inch 1440p monitor a pixel is about 0.23 mm; on a 24-inch 1080p monitor about 0.28 mm; on a modern phone often under 0.06 mm. That is why a single defective pixel is far harder to see than people expect, and why practising on the simulator first makes a real inspection more reliable.
What this test checks
- What each defect type looks like at true pixel size
- How dead, stuck, bright and subpixel faults differ at subpixel zoom
- Which backgrounds make each defect visible — and which hide it
Related tests
Dead Pixel Test
White, black, RGB and gray slides — the core check.
Stuck Pixel Color Cycling
Rapid color cycling that sometimes releases a stuck subpixel.
Stuck Pixel Test
Black-first sequence built to make a stuck subpixel show itself.
Screen Color Test
Extended color set including cyan, magenta and yellow.
Not sure what you are seeing?
Run diagnosisSave your observations
Create a report