Screen Test
Check your screen for dead pixels or stuck sub‑pixels. Fullscreen colors with click to cycle.
Dead pixel: appears black on all colors.
Stuck pixel: appears colored on black/white (e.g. red pixel on white screen = stuck green+blue).
How to Use Screen Test
- Click Start Fullscreen Test and grant fullscreen permission when the browser prompts you.
- The screen will turn solid white. Click anywhere to cycle through the colors: white → black → red → green → blue → gray gradient.
- On each color, inspect your screen closely — look for any pixel that appears black (dead) or a bright dot of the wrong color (stuck).
- Press the Escape key or click repeatedly to reach the end and exit fullscreen.
Benefits of Screen Test
- No software to install; works on any device with a browser and a screen, including laptops, monitors, tablets, and phones.
- Full‑screen mode hides all UI clutter so you see the entire display, making tiny dead pixels easier to spot.
- Gray gradient test can also reveal backlight bleeding and banding issues that pure colors might miss.
- Quick test sequence — you can run the whole battery of colors in under 60 seconds, ideal for checking a device before purchase.
Frequently Asked Questions
How do I tell the difference between a dead pixel and a stuck pixel?
A dead pixel stays black on every color. A stuck sub‑pixel shows a constant color (red, green, or blue) that disappears only on the matching colored background.
Can a stuck pixel be fixed?
Sometimes. Gently massaging the area with a soft cloth while a pixel‑fixing video runs can unstick a pixel. The test helps you identify which sub‑pixel is stuck.
Should I test my screen right after buying it?
Yes, run the test immediately and again before the warranty expires. Most manufacturers allow returns for dead pixels only within a specific window and threshold count.
Is Screen Test free and private?
Yes — it is 100% free, needs no sign-up, and everything runs in your browser; your data never leaves your device.