How to test for dead pixels
Follow these steps to run a dead pixel test and locate defects on your display:
- Clean your screen: Wipe your screen with a microfiber cloth. Dust particles and smudges can easily be mistaken for pixel defects.
- Set brightness to maximum: Increase your monitor brightness to 100%. Bright light makes anomalies easier to spot.
- Launch the test panels: Click the test colors above to enter full-screen mode.
- Scan your screen: Inspect every area of your display against each solid color.
- Look for anomalies: Dead pixels appear as permanent black dots. Stuck pixels show a fixed red, green, or blue color. Hot pixels appear white.
Types of pixel defects explained
Modern screens are made of millions of pixels, and each pixel contains red, green, and blue sub-pixels. When transistors inside the display panel malfunction, they produce different types of defects:
Dead pixel
A dead pixel is permanently turned off, appearing as a black dot on your screen. It happens when all three sub-pixels fail to receive power. Since the transistor is completely dead, this defect is usually permanent.
Stuck pixel
A stuck pixel stays locked in a single color state, showing up as a bright red, green, or blue dot. Because it still receives power, you can often fix it using software utilities that cycle colors rapidly.
Hot pixel
A hot pixel is a pixel where all three sub-pixels are stuck in the "on" state. This creates a bright white dot that is highly visible, especially when viewing dark backgrounds. You can run a white screen test to verify bright pixels.
How to fix a stuck pixel
If you find a stuck pixel during your dead pixel test, you may be able to repair it. Since the sub-pixel transistors still receive power, you can try these two popular repair methods:
- Software color flashing: Run a rapid pixel-repair utility (like JScreenFix) for 30 to 60 minutes. These tools flash colors rapidly to stimulate the stuck transistor.
- Gentle pressure application: Turn off your display. Wrap a microfiber cloth over a pen cap or pencil eraser. Press gently on the stuck pixel while turning the display back on, then release. Caution: Excessive pressure can permanently destroy surrounding sub-pixels.
Note that dead pixels cannot be revived with software or pressure. If these fixes fail, check if your display is covered under warranty.
Manufacturer dead pixel warranty policies
Whether a dead pixel qualifies for a warranty replacement depends entirely on the manufacturer's policy. The ISO 13406-2 standard defines four defect classes, but most consumer monitors follow individual vendor thresholds:
| Manufacturer | Policy Name | Dead pixel threshold for replacement |
|---|---|---|
| Dell (UltraSharp) | Premium Panel Exchange | Zero bright pixel defects during limited hardware warranty period for UltraSharp, Professional, and Alienware monitors (last checked June 2026). Dark pixel thresholds vary; check your exact model. |
| LG | Zero Bright Dot | Representative guidance: Stated limits depend on monitor class; select high-end lines may offer coverage for 1 bright pixel. Check exact regional terms for your model. |
| ASUS (ROG/ProArt) | Dead Pixel Free | Zero bright dots for select lines under the Dead Pixel Free policy (last checked June 2026). Standard models typically allow up to 3 to 5 defective pixels. Check your exact model. |
| Samsung | Standard Warranty | Representative guidance: Custom model classes and regional terms apply. Standard lines often follow Class II criteria. Verify your exact model and region. |
| BenQ | Standard Warranty | Representative guidance: Generally follows Class II specifications with varying limits for bright and dark pixels. Check the exact warranty tier for your region. |
| Budget / Generic | ISO 13406-2 Class III | Representative guidance: Often matches Class III standards allowing a higher threshold of defects. Refer to your user manual. |
Dead pixel policies vary by model, region, panel type, and warranty plan. Always verify the exact policy for your device before filing a claim.
Beyond dead pixels: additional hardware checks
- Verify Native Resolution: Ensure your OS display settings match your monitor's native resolution. Using a Full HD (1080p) setting on a QHD (1440p) or 4K Ultra HD panel will cause blurring.
- Check Refresh Rate: High-end monitors default to 60Hz out of the box. Go into your display settings and maximize the refresh rate (e.g., 144Hz or 240Hz).
- Cable Bandwidth: If you are unable to achieve your maximum resolution or 10-bit color depth, verify you are using a certified DisplayPort 1.4 or HDMI 2.1 cable.
- DPI and Scaling: On high-density screens (like Apple Retina displays), the monitor pixel density (PPI) is so high that scaling is required. This increases your Device Pixel Ratio (DPR), ensuring that web pages render with sharp CSS pixels while maintaining a proper physical screen size and aspect ratio. Before running your dead pixel test, make sure your OS is set to your display's native resolution — you can check your native screen resolution with the live tool.
- Backlight Bleeding: To verify if your screen leaks light along the edges, you can run a backlight bleed test to inspect the frame assembly.