This free online pixel test, also called a dead pixel test, fills your screen with solid black, white, red, green, and blue so a dead, stuck, hot, or subpixel defect stands out against a background that everyday content would hide. It runs entirely in your browser with no app, account, or download. Start the test above, then use the sections below to match the dot you see to what it likely means and the next step to take.
How to Run a Pixel Test Online
Clean the screen gently first and avoid pressing on the panel.
- 1
Prepare the display
Use the device at its normal resolution, turn off night mode, color filters, and overlays, and set a moderate brightness.
- 2
Enter fullscreen
Start the test above and let the color fill the screen so browser bars and the camera cutout do not hide a dot.
- 3
Step through every color
Move through black, white, red, green, and blue on any device, plus the gray, gradient, and pattern screens on desktop. Look from normal distance, then closer.
- 4
Mark and record what you see
Click or tap any suspicious dot to mark it for the summary, and note its color, background, location, and whether it also appears in a screenshot or on another input.
- 5
Choose the next step
Match the dot to the result guide below. Use the fixer only for a plausible stuck or hot pixel, and document a persistent defect before contacting support.
What Each Pixel Test Color Shows
No single color is proof. Compare the same spot across the full sequence.
Swipe sideways to compare columns.Scroll table to view all columns.
| Test screen | What it helps you find |
|---|---|
| Black | Bright white or colored dots (stuck, hot, or lit subpixels) and any glow around them |
| White | Dark or missing dots (dead or dark pixels), dust, and pressure marks |
| Red | Green or blue subpixel problems at a fixed point |
| Green | Red or blue subpixel problems at a fixed point |
| Blue | Red or green subpixel problems at a fixed point |
| Gray | Uneven brightness, faint retention, or subtle tint across an area rather than one dot |
| Gradient and pattern (desktop) | Banding, scaling, sharpness, and line or row and column faults |
What Your Pixel Test Result Means
The test shows you solid colors and lets you mark dots; it does not label them for you. Match what you saw to a result below to find the likely category, how far to trust it, and what to do next. Behavior across colors and whether the dot appears in a screenshot are your strongest clues.
Dark dot on white and colors
Moderate confidence- What you saw
- A dark or unlit dot that shows up on white, red, green, and blue, and usually disappears in a screenshot.
- What it means
- Consistent with a dead or dark pixel, but dust, a surface chip, or a tiny overlay can look identical. This does not confirm a dead pixel or decide warranty eligibility.
Next: Clean the screen gently and retest; if it stays and is missing from screenshots, record it for your warranty documentation.
Red, green, or blue dot
Confirm by repeating- What you saw
- A small colored dot fixed at one spot, most obvious on the complementary color, and absent from screenshots.
- What it means
- Consistent with a stuck subpixel that is locked on. A localized, stable colored dot is the best candidate for a repair attempt. A colored dot that moves or changes with content is more likely software than a stuck pixel.
Next: If it is stable and localized, try the Stuck Pixel Fixer.
Bright white dot on black
Moderate confidence- What you saw
- A bright point that stands out on the black screen and stays lit.
- What it means
- Consistent with a hot or bright pixel. A broad glow around it instead of a sharp point points to a backlight or panel issue, not a single pixel. This cannot prove the pixel is permanently stuck on or name the failed component.
Next: A short session may revive it; if it stays, document it. Open the Stuck Pixel Fixer.
Dot appears in a screenshot
High confidence- What you saw
- The same dot is captured when you take a screenshot and appears on another display too.
- What it means
- This is software, content, or rendering, not the panel. Physical pixel faults are recorded from the image buffer, so they do not show up in screenshots. Do not run a pixel fixer for this; it will not help a software artifact.
Next: Restart, update, disable overlays, and test another app, browser, or input before treating it as hardware.
Dot on the panel but not in screenshots
High confidence- What you saw
- You can see the dot with your eyes, but it never appears in a screenshot.
- What it means
- This is a display-side dot. Use its color to classify it: dark points lean dead, colored points lean stuck, and bright points on black lean hot. Screenshot behavior points to display-side, but it does not name the exact defect or prove warranty eligibility.
Next: Classify it by color using the cards above, then document it before contacting support.
Line, patch, glow, or shadow
High confidence- What you saw
- The mark is not a single dot. It is a line, a broad patch, edge glow, or an image-shaped shadow.
- What it means
- This is not a pixel problem. Lines and patches suggest connection or physical damage, edge glow suggests backlight bleed, and an image-shaped shadow suggests retention or burn-in. A pixel test cannot diagnose these, and a pixel fixer will not help.
Next: Switch to the matching test in the next section instead of treating it as one pixel.
Dead Pixel vs Stuck Pixel vs Hot Pixel
A dead pixel never lights up, so it looks like a black dot on white and bright colors and is the least likely to recover. A stuck pixel is frozen with one or more subpixels locked on, so it shows as a fixed red, green, or blue dot and is the best candidate for a fixer. A hot pixel is stuck bright and shows as a white dot on black. A subpixel defect is a single color channel that is always on or always off, so it is clearest on the complementary color. In every case, a real panel defect stays at the same coordinate across colors and does not appear in a screenshot.
Pixel Test vs Stuck Pixel Fixer: the test finds and classifies the dot, while the fixer only tries to revive a plausible stuck or hot pixel. If a small colored or bright point stays fixed and is absent from screenshots, run the Stuck Pixel Fixer. Do not use the fixer on a dark dead pixel, or on lines, patches, or glow.
If It's Not a Single Pixel
If the mark is a line, a broad patch, edge glow, or an image-shaped shadow, a pixel test is the wrong tool. Match the symptom to the right check below.
Backlight Bleed Test
Edge glow or bright clouds along the sides on a black screen.
Run test
Burn-In Test
A faint image-shaped shadow that follows what was on screen before.
Run test
Screen Color Test
Overall tint, banding, or uneven color rather than one fixed dot.
Open test
Document Damage for Warranty
Lines, cracks, or pressure marks you need to record before contacting support.
View checklist
Pixel Test for Phones, Monitors, Laptops, Tablets, and TVs
Monitor
Test at native resolution, then swap cable, port, and source device. Photograph the dot with the on-screen menu visible.
Laptop
Compare the built-in panel against an external display. A mark on only the laptop panel points to the panel itself.
Phone
Turn off night mode and color filters, and check around the camera cutout separately. Never press, tap, or heat the screen.
Tablet
Check both orientations with cases and protectors removed. Pressure marks and touch-layer faults are larger than one pixel.
TV
Use the built-in browser only if it shows colors without scaling; otherwise connect a known-good source and compare inputs.
OLED vs LCD
On OLED, keep brightness moderate and sessions short; image-shaped shadows are usually retention. On LCD, use black and white to separate a point from backlight glow.
What This Browser Pixel Test Can and Cannot Prove
This is a browser test, so it can only show colors and record what you mark. It fills the screen with solid colors (five on phones and up to ten on desktop, including gray, gradient, checkerboard, line, and moving-square screens), lets you click or tap suspicious dots, and returns a summary with your mark count and a location map. It does not scan or automatically label pixels; you classify what you see using the guidance above.
The screenshot check is your most reliable tell: a capture records the image the device sends, not the physical panel, so a real pixel fault usually will not appear in a screenshot while a software artifact will. Within these limits the test can strongly suggest a category and the right next step, but it cannot prove the electrical cause, name the failed component, or decide warranty eligibility.
Pixel Test vs Alternatives
How this test compares to basic color testers, monitor suites, and manufacturer diagnostics.
Swipe sideways to compare columns.Scroll table to view all columns.
| Capability | ScreenDetect Pixel Test | Typical pixel tools |
|---|---|---|
| Fullscreen colors | Black, white, red, green, and blue, plus gray, gradient, and pattern screens on desktop. | Basic testers show a few solid colors; monitor suites add broader quality patterns. |
| Result interpretation | Named results that separate dead, stuck, hot, subpixel, software, and not-a-pixel symptoms. | Most tools locate a dot but leave classification to you. |
| False-positive checks | Guides cleaning, screenshot, app, input, and scaling checks before you conclude. | Usually limited to visual inspection of solid colors. |
| Next-step routing | Routes stuck or hot candidates to repair and other symptoms to the correct test or support. | Often stops after locating a suspicious pixel. |
| Access | Runs in the browser with no app or account. | Usually browser-based; manufacturer diagnostics vary by device. |
Sources checked
These official support pages were checked on June 29, 2026 for troubleshooting steps, diagnostics, service limits, and more.
- Dell Display Pixel Guidelines · DellPixel defect terminology and support guidance.
- HP Pixel Policy · HPManufacturer pixel-defect policy context.
- Lenovo LCD pixel policy · LenovoLCD pixel and subpixel policy guidance.
- W3C Understanding Success Criterion 2.3.1 · W3CSafety guidance for flashing content.
Pixel Test FAQ
What is a pixel test?
A pixel test fills the display with uniform colors and patterns so isolated dots, lines, tint, retention, and uniformity problems are easier to see.
How do I test for dead pixels online?
Run the test fullscreen and inspect black, white, red, green, and blue screens. A consistently dark point on bright backgrounds may be a dead pixel, after dust and surface marks are ruled out.
What color is best for finding a dead pixel?
White and the primary-color screens make dark or missing subpixels easier to see. Use the entire sequence because one screen alone can hide a defect.
How can I tell a dead pixel from a stuck pixel?
A dead pixel is usually dark, while a stuck pixel commonly remains red, green, or blue. Behavior can vary, so compare several backgrounds and screenshots.
What is a hot pixel?
A hot pixel remains unusually bright, often white on a dark screen. On cameras the term can also describe sensor behavior, so this page applies specifically to displays.
Can a pixel test fix a pixel?
No. The Pixel Test is diagnostic. The Stuck Pixel Fixer uses changing colors and is only a reasonable next step for a plausible stuck or hot pixel.
Why does the dot appear in my screenshot?
A mark captured in a screenshot is likely being produced by software, content, or the graphics pipeline rather than a physical pixel at that panel coordinate.
Why is the dot missing from screenshots?
That result supports a display-side issue, but it does not identify the exact failed component. Compare another input or external display where possible.
Does this work on phones, tablets, laptops, monitors, and TVs?
Yes, if the browser can show the test fullscreen and without scaling artifacts. Device controls, cutouts, and TV browser scaling can affect what you see.
Should I press or rub a stuck pixel?
No. Pressure, tapping, twisting, or heat can damage panel layers and makes warranty evidence harder to interpret.
How many dead pixels qualify for warranty service?
Policies vary by manufacturer, model, region, pixel type, and defect location. Save evidence and check the exact support policy for your product.
When should I stop testing?
Stop if flashing content causes discomfort, if the panel is cracked, swollen, wet, very hot, or changing under pressure. Move to documentation and professional support.
What is a pixel checker?
A pixel checker is another name for a pixel test: a tool that fills the screen with solid colors so you can spot and classify a dead, stuck, or hot pixel. This page is that tool, and it runs free in your browser.
Can dust look like a dead pixel?
Yes. Dust or a surface speck can look like a dark dot on a white screen. Clean the screen gently and retest; a mark that wipes away, moves, or changes with cleaning is debris, not a dead pixel.
Is a white dot dead or hot?
A dead pixel stays dark, so a bright white dot is not dead. A white dot that stays lit on a black screen is usually a hot pixel. A broad glow around it points to a backlight or panel issue instead of a single pixel.
What does a red, green, or blue dot mean?
A fixed red, green, or blue dot means one subpixel is stuck on. If it stays at the same spot and is absent from screenshots, it is the best candidate for the Stuck Pixel Fixer.