Online Screen Test

Check your display monitor for dead pixels, stuck subpixels, color uniformity, and backlight bleeding.

Ready when you are

Click below to start full-screen solid color tests across red, green, blue, black, and white.

Display output: Primary Display Panel
Display analysis runs locally in your browser with zero server uploads.
Screen inspection Inspect display with solid colors or run automatic cycling:
Custom color:
Display panel inspection complete
Display panel inspected across 5 primary colors with normal uniformity.
95/100
Technical details & diagnostics
Display resolution 1920 × 1080
Device Pixel Ratio 1x DPR
Color depth 24-bit sRGB
Subpixel format Standard RGB Stripe
Fullscreen mode blocked

Your browser has blocked fullscreen mode. Follow the 3 steps below to allow:

1 Fullscreen must be triggered by a direct user tap or click.
2 Ensure browser kiosk restrictions or popup blockers are disabled.
3 Click Try again below.
Screen API unavailable

We could not query your monitor's display properties. Please review the 3 items below:

1 Check your monitor HDMI, DisplayPort, or USB-C video cable.
2 Verify display scaling and refresh rate in your operating system Display Settings.
3 Update your GPU graphics card driver to the latest WHQL release.
Preview State:
Pure Black 1 / 13
Click /; Next • Space: Auto • Esc: Exit
Next recommended check Test your microphone input volume and clarity
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How to check your screen in 3 steps

1 Clean your monitor surface with a dry microfiber cloth to remove dust particles.
2 Click any color swatch above to display a pure solid background across your entire monitor.
3 Inspect the display for black dots (dead pixels) or bright colored specks (stuck pixels).

Screen troubleshooting guide

Review common screen defects, causes, and recommended solutions:

Symptom Probable Cause Concrete Fix
Black dot on white background Dead pixel where the thin-film transistor (TFT) has permanently failed. Dead pixels are unrepairable; check your warranty coverage under the manufacturer pixel policy.
Bright red, green, or blue dot Stuck subpixel with liquid crystal cell frozen in the open state. Run rapid RGB screen flashing utilities for 15 minutes to attempt to unfreeze the subpixel crystal.
Yellowish clouding on screen edges IPS backlight bleed caused by tight bezel clamping or pressure on the panel. Slightly loosen monitor bezel screws or reduce screen brightness; bleed is visible primarily in dark rooms.
Ghost images retain after closing apps OLED burn-in or temporary IPS image persistence. Run the monitor built-in Pixel Refresh / Pixel Clean cycle and avoid static images for long periods.

About this screen diagnostic test

The Sharing.io.vn screen test operates via the W3C Fullscreen API to present pure, uncompressed chromatic fields across your monitor. Standard desktop displays are constructed from millions of individual subpixels arranged in red, green, and blue (RGB) stripes. By illuminating pure primary colors (R, G, B) and secondary neutrals (Black, White), every individual subpixel transistor is forced into its on and off states.

Privacy guarantee: No screen content, resolution fingerprints, or personal data are collected or transmitted.

Last updated: October 25, 2026 • Verified for IPS, VA, TN, OLED, and Mini-LED displays.

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Frequently asked questions

What is the difference between a dead pixel and a stuck pixel?
A dead pixel is completely unpowered and remains permanently black on white or bright backgrounds. A stuck pixel has one or two subpixels stuck in the open transmission state, causing it to appear as an illuminated red, green, or blue dot on dark backgrounds.
What causes backlight bleeding on IPS monitors?
Backlight bleeding occurs when the outer frame bezel puts uneven mechanical pressure on the liquid crystal panel, allowing edge LED light to leak around corners. This is visible primarily when displaying black content in a dark environment.
Can stuck pixels be fixed with software?
Stuck pixels can sometimes be revived by rapidly cycling high-contrast color patterns for 10 to 30 minutes, which exercises the liquid crystal molecules. Dead pixels with broken electrical transistors cannot be fixed by software.
How many dead pixels qualify for a manufacturer replacement?
Most monitor manufacturers follow ISO 9241-307 Class II guidelines, which permit up to 2 permanently bright pixels, 5 dark pixels, or a total of 5 defective subpixels per million pixels before considering the panel defective under warranty.
Does this test support HDR and OLED monitors?
Yes. On OLED displays where each pixel is self-emissive, testing with pure black ensures every functional pixel is completely dark, revealing any anomalous stuck subpixels with extreme contrast.
How do I exit the fullscreen test mode?
You can exit fullscreen mode at any time by pressing the ESC key on your keyboard or by clicking/tapping anywhere on the screen.