100% in your browser — nothing to install
Dead Pixel Test
Check your screen for dead, stuck and bright pixels in under a minute.
Monitor · Laptop · Phone · TV
No download · No sign-up · Runs in your browser
Before you start
- 1
Clean obvious dust or fingerprints — dust looks exactly like a dead pixel.
- 2
Use the display at its normal resolution and a comfortable brightness.
- 3
Dim the room lights, especially for the black and near-black slides.
- 4
Inspect the whole screen on each color, corner to corner.
See something? Press M (or long-press on a phone) to mark exactly where it is. Marked positions carry over into your screen test report.
Controls
- Space / →
- Next pattern
- ←
- Previous pattern
- M
- Mark an issue
- F
- Toggle fullscreen
- H
- Hide the interface
- A
- Auto-cycle
- Esc
- Exit
On a phone: swipe to change pattern, tap to advance, long-press to mark an issue.
What each color reveals
White
Dead pixels show as black dots. The most important slide for finding true dead pixels.
Black
Stuck pixels glow as bright white or colored dots. Also reveals backlight bleed in a dim room.
Red / Green / Blue
Each primary color isolates one subpixel, so a partially failed pixel stands out on one slide only.
Gray levels
50% gray exposes uniformity issues; 5% gray reveals OLED banding and dark-area blotches.
Testing an OLED? Run the dedicated 5% gray uniformity test, or open and download gray test images for a TV or offline display.
What did you see?
Different defects need different next steps — and some "defects" are just dust. Pick the closest description to get a likely cause and what to do about it.
A black dot that stays on light backgrounds
Likely a dead pixel
A pixel that stays black on white, red, green and blue backgrounds is receiving no power or no signal. True dead pixels are a hardware fault and software cannot switch them back on.
Next step: Count the dots and note their position, then check the return window or the manufacturer dead pixel policy for your device. A report makes the conversation with the seller easier.
A bright white, red, green or blue dot on black
Likely a stuck subpixel
A dot that glows in one color on a black background is usually a subpixel stuck on. Unlike dead pixels, stuck pixels sometimes recover after rapid color cycling.
Next step: Try the Stuck Pixel Fixer for 10–20 minutes, then re-run the test. If the device is new, a return or exchange is still the safer option.
Cloudy glow or bright patches near the screen edge
Backlight bleed or IPS glow
Uneven light around edges and corners on a dark screen comes from the backlight, not from individual pixels. IPS glow shifts when you change your viewing angle; backlight bleed stays in place.
Next step: Re-test in a dim room at your normal brightness and move your head side to side. Mild edge glow is common on LCD panels; strong bleed on a new device can justify an exchange.
Dark vertical or horizontal bands on gray
Gray uniformity issue
Bands or large dull patches that appear on mid-gray backgrounds are a panel uniformity problem, sometimes called the dirty screen effect. OLED panels can also show faint vertical banding in dark gray.
Next step: Confirm with several gray levels at 50–100% brightness. Mild non-uniformity is normal; strong banding visible in everyday content is worth reporting to the seller.
A faint image or shadow that stays on screen
Burn-in or image retention
A leftover outline of a logo, taskbar or scoreboard is image retention. On OLED screens it can become permanent burn-in; on LCD it usually fades after the screen shows varied content.
Next step: Run the burn-in check to see how visible the retention is at different gray levels. If it fades within hours it was temporary retention, not burn-in.
The spot disappears after cleaning the screen
Dust or a smudge — not a pixel defect
Dust, fibers and fingerprints sit on top of the glass and move or vanish when wiped. A pixel defect never moves and never changes size.
Next step: Clean with a dry microfiber cloth and re-run the test. If the spot is gone, your panel is fine.
An area of the touch screen does not respond
Touch digitizer issue
Touch input is handled by a separate layer from the pixels. A screen can look perfect and still have dead touch zones, often after a drop or screen replacement.
Next step: Map the unresponsive area with the touch grid test. Restart the device and remove any screen protector before concluding it is a hardware fault.
Nothing — the screen looks clean
No visible pixel defects
If every full-screen color looked even with no dots, bands or glow, your panel passed the visual check.
Next step: Save a dated report as proof of condition — useful for warranty windows, selling a device or verifying a used purchase.
More screen tests
A dead pixel test is only the start — these cover the rest of a full screen inspection.
Screen Diagnosis
Answer a few questions to narrow down what you are seeing.
Complete Monitor Test
Quick, Full and OLED suites in one run.
Dead Pixel Simulator
See what dead, stuck and bright pixels look like at real size.
Stuck Pixel Color Cycling
Rapid color cycling that sometimes releases a stuck subpixel.
Screen Uniformity Test
Gray levels that expose bands, clouding and dirty screen effect.
5% OLED Gray Test
5% grey banding check, near-black steps and a 3×3 uniformity map.
Backlight Bleed Test
Dark slides plus an angle check that separates glow from bleed.
OLED Burn-in Test
Gray slides that make retained images visible.
Gradient / Banding Test
Smooth ramps that show color banding and bit-depth issues.
Ghosting Test
Moving patterns that reveal trails, smearing and overshoot.
Refresh Rate Test
Frame cadence your browser actually observes, with the caveats.
Screen Color Test
Extended color set including cyan, magenta and yellow.
Touch Screen Test
Paint a grid with your finger to find dead touch zones.
Screen Test Report
Turn your findings into a dated, printable report.
Gray Test Images & Downloads
Fullscreen grey images and 4K or 8K patterns for offline testing.
What is a dead pixel?
A dead pixel is a picture element that no longer lights up. It looks like a tiny, fixed black dot on white and other bright backgrounds, and it cannot be fixed by software. A stuck pixel is frozen on: it glows red, green, blue or white on a black background — and rapid color cycling can sometimes release it.
Getting this distinction right matters, because it decides whether a fixer tool is worth trying or whether you should go straight to a return or warranty claim.
Dead pixel
Black dot on white — pixel is off
Stuck pixel
Colored dot on black — subpixel frozen on
Test by device
Each device page adjusts the color sequence and instructions to the panel type and its typical problems.
Turn your test into a report
Record the device, the defects you found and where they are, then export a dated report as an image, a printable page or plain text. Useful for warranty claims, selling a device, verifying a used purchase or documenting a new monitor on unboxing day. Everything is generated locally — nothing is uploaded.
Create a Screen Test ReportFrequently asked questions
What is a dead pixel?
A dead pixel is a pixel that no longer lights up and appears as a small black dot on any bright background. It usually means the pixel receives no power and it cannot be fixed by software.
How does this dead pixel test work?
The test fills your entire screen with solid colors — white, black, red, green, blue and two gray levels. Each color makes a different kind of defect visible. You look closely at each slide and note any dots, bands or glow.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays black because it receives no power. A stuck pixel stays lit in one color — red, green, blue or white — because a subpixel is frozen on. Stuck pixels can sometimes be revived with rapid color cycling; dead pixels cannot.
Can this website fix dead pixels?
No — and no software can. Truly dead pixels are a hardware fault. Our Stuck Pixel Fixer can sometimes revive stuck pixels, but for dead pixels your options are warranty service, an exchange or a panel replacement.
Is my data uploaded anywhere?
No. Every test runs entirely in your browser. Nothing is uploaded, no account is needed, and reports you create are generated locally on your device.
How many dead pixels are acceptable?
It depends on the manufacturer. Many follow ISO 9241-307 classes that allow a small number of defects before a panel qualifies for warranty replacement, while premium policies replace panels with even a single bright dead pixel. Check your brand’s policy and your retailer’s return window.
Screen defect guides
All guides →Dead Pixel vs Stuck Pixel: How to Tell Them Apart
Dead pixels stay black, stuck pixels stay lit. Learn how to tell them apart in two minutes and why the difference decides what you should do next.
What Does a Dead Pixel Look Like?
A dead pixel is a tiny black dot that stays in the same place on every bright background. Here is how to recognize one — and everything that merely looks like one.
Can a Dead Pixel Be Fixed?
Honest answer: software cannot fix a truly dead pixel. Here is what can and cannot be fixed, what actually works for stuck pixels, and when to use your warranty instead.