How to check your screen for dead or stuck pixels
- Clean the display carefully with the method recommended by its manufacturer, so dust does not look like a pixel defect. Reduce reflections and choose normal comfortable brightness.
- Press Start screen test. A solid color covers the available screen. Where the Fullscreen API is allowed, the page requests fullscreen after your click; otherwise a full-window overlay still lets you inspect the display.
- Cycle through black, white, red, green, blue and gray. Look slowly across the screen, especially the edges, without staring at a bright display for long periods. The on-screen control changes the color; press Escape or Exit to leave.
- Compare any suspicious point across several colors. Take a photograph with a separate camera if you need to document it for a warranty claim.
The test draws solid fills in the browser. It does not use your webcam, access display hardware diagnostics or transmit any screen images. Pixels are not inspected automatically: the viewer must observe and decide whether a defect is present.
Dead pixels, stuck pixels and dust
A display pixel generally contains red, green and blue subpixels. A dead pixel may stay black even on a white screen. A stuck subpixel may remain bright or display the wrong channel, looking colored on a black background or disappearing against some solid colors. These simplified descriptions are useful for a visual check but cannot conclusively identify the internal fault.
Dust, fingerprints, the texture of a matte screen protector and compression artifacts in a screenshot can look similar. Unlike defects in the physical panel, dirt changes when the viewing angle or lighting changes and may disappear after proper cleaning. A screenshot records the software image, not the physical state of the display, so a screenshot usually cannot prove a dead physical pixel.
Why test six colors?
White lights all three channels strongly and makes dark spots easier to notice. Black reveals bright stuck subpixels or light leakage. Red, green and blue individually show whether a color channel fails or stays on. Mid-gray can make certain contrast and uniformity issues more obvious. This page uses static fills only; it does not attempt rapid flashing, pixel repair or high-frequency patterns.
Some displays use scaling, unusual subpixel structures, dithering or local dimming. Depending on brightness and the screen technology, a tiny imperfection might be difficult to see. If you need to evaluate a new television or monitor, check it at its native resolution, with normal settings and at a practical viewing distance.
What to do when you find a problem
- Check a different screen input or application to rule out a software cursor, overlay or cable problem.
- Use another solid color to see whether the same physical spot remains affected.
- Consult the manufacturer or seller about its own pixel-defect warranty policy. There is no universal allowance that applies to every device and display class.
- Avoid pushing the panel or running aggressive flashing videos as a supposed fix; such actions can make matters worse.
For a separate test of input rather than output devices, use our keyboard tester or reaction time test. The screen tester is not a professional display calibration or color-accuracy instrument.
Frequently asked questions
Does this repair stuck pixels?
No. It only displays steady test colors. Avoid forceful pressure or rapid flashing videos as a supposed fix.
Can I take a screenshot to prove a dead pixel?
Usually not. Screenshots capture the rendered image, not the panel defect. Take a photo of the physical display instead.
Does the page test automatically?
No. You visually inspect the display while the browser shows a uniform fill.
How do I exit the test?
Use the visible Exit button or Escape key. If fullscreen is active, your browser can also exit it.
Last updated: October 17, 2026