Dead Pixel Test
Cycle through 12 fullscreen solid colors to expose dead, stuck, and hot pixels on any monitor, laptop, phone, or TV. The fastest way to verify a panel before your return window closes.
Why use this dead pixel test
12 solid color presets
White, black, red, green, blue, cyan, magenta, yellow, orange, and three grey shades surface every pixel defect type.
Fullscreen frame-by-frame scan
Each color fills the entire viewport so a single misfiring sub-pixel becomes obvious against a uniform background.
Keyboard shortcuts
Arrow keys advance colors instantly. Press F for fullscreen, Esc to exit. Faster than any downloaded checker.
Works on every device
Phone, tablet, laptop, desktop, or TV — anything with a browser can be tested without installing software.
What is a dead pixel
A dead pixel is a single pixel on a display panel that does not illuminate correctly. The most common form is a permanently black dot caused by a failed transistor, but the term is also used loosely to cover stuck pixels (a sub-pixel locked on in red, green, or blue) and hot pixels (always-on white dots caused by sensor or driver leakage).
Each display pixel is made of three sub-pixels — red, green, and blue — each driven by its own thin-film transistor. If even one transistor fails at the factory or degrades over time, the corresponding sub-pixel stays in a fixed state and becomes visible against uniform color fields. Modern panels are graded by ISO 9241-307 classes, which dictate how many defective sub-pixels are tolerated before a panel is rejected.
Testing is the only way to find these defects. A single dead pixel may be invisible during normal use but glaring during a fullscreen color test. Run the test on any new display within the return window — most retailers refuse exchanges after 14-30 days.
How to test for dead pixels
Step 1: Clean the screen
Wipe the panel with a microfiber cloth so dust doesn't get mistaken for a dead pixel.
Step 2: Dim the room
Lower ambient light so your eyes can focus on faint pixel-level defects instead of reflections.
Step 3: Launch the test
Click any color swatch above. The display goes fullscreen instantly with that color.
Step 4: Scan systematically
Move your eyes left-to-right, top-to-bottom. Look for any dot that differs from the surrounding field.
Step 5: Note location and color
Mark defects with a sticky note on the bezel so you can re-test after a pixel massager or replacement.
What causes dead pixels
Manufacturing defects
A transistor that doesn't switch on leaves a permanently dark (dead) sub-pixel. Common on cheaper panels.
Stuck sub-pixels
A sub-pixel locked on (red, green, or blue) shows as a tiny colored dot. Sometimes fixable with gentle pressure or cycling.
Hot pixels
Always-on bright dots caused by leakage current. More visible on long exposures and dark backgrounds.
Physical impact
Pressure, drops, or shipping damage can crack internal connections, producing new defects over time.
Frequently asked questions
Testing tips
- Test in a dark room — reflections hide faint defects that low light would reveal.
- Sit at your normal viewing distance first, then move within 10 cm to catch tiny defects.
- Check every color, not just white. Some defects only show on red, green, or blue fields.
- Take a photo of any defect with your phone for evidence when filing a warranty claim.
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How to Find Dead Pixels Before Your Return Window Closes
You just unboxed a brand new monitor. It looks gorgeous — crisp text, vivid colors, no obvious defects. So why bother running a dead pixel test? Because the most common panel defects are invisible during everyday use and only show up against solid fullscreen colors. By the time you notice one in normal use, your 14-day return window may have already closed.
The smart move is to test every new display within 24 hours of unboxing. Open the dead pixel test above and cycle through all 12 colors. Start with pure white — this exposes stuck-on sub-pixels as tiny colored dots — then black, which reveals hot pixels as faint glowing specks. Red, green, and blue isolate individual sub-pixel channels, while cyan, magenta, and yellow surface complementary channel failures. A defect that hides on white might leap out on magenta.
Test in a dim room. Reflections on the panel mask faint pixel-level defects, and your eyes need a few seconds to adapt to each color before you scan systematically left-to-right, top-to-bottom. Sit at your normal distance first, then lean in to within 10 cm for a closer pass. Take a phone photo of anything suspicious — retailers often ask for evidence when processing an exchange.
If you find a defect, check your warranty terms immediately. Most manufacturers grade panels by ISO 9241-307 classes that permit a handful of defective sub-pixels, but premium displays and Apple products often ship with a zero-dead-pixel guarantee. Either way, you must act before the return window expires. Once that closes, you're stuck with the panel's RMA process, which can take weeks.
Run the same test alongside our backlight bleed test and burn-in test to catch every common panel defect in a single session. Five minutes now can save you months of regret.
Test your screen for dead pixels now
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