Dead Pixel Checker (Screen Test)
The simplest way to find dead or stuck pixels on your monitor. Supports 4K, OLED, and mobile screens. 100% browser-based, no installation required.
Monitor Diagnostic Center
Run a comprehensive visual inspection to identify dead, stuck, or hot pixels on your display.
Works perfectly on Desktop, iPhone, iPad, and Android devices
What is This Tool
The Screen Diagnostic Suite is a high-performance utility tailored for detecting hardware defects in modern displays. Unlike static images, this browser-based application utilizes hardware acceleration to render pure color spectrums across every physical pixel of your monitor. It serves as a vital quality-control tool for new device inspections, allowing users to differentiate between permanent dead pixels and recoverable stuck pixels using high-frequency stimulation patterns.
How to Use
Follow these professional steps to ensure a comprehensive display health check:
- Prepare Your Environment - Clean your screen surface with a microfiber cloth to ensure dust particles are not mistaken for pixel defects.
- Launch Fullscreen Mode - Click the "Start Fullscreen Test" button to remove browser UI elements for a distraction-free inspection.
- Cycle Through Colors - Click or tap the screen to rotate through black, white, and primary RGB colors to find anomalies.
- Observe Carefully - Inspect the display at various angles; look for bright spots on black or dark spots on white backgrounds.
- Deploy the Fixer - If a pixel is stuck on a specific color, run the "Stuck Pixel Fixer" for at least 10-30 minutes to stimulate it.
- Verify the Results - Exit the tool and re-run the test to confirm if the flickering patterns have successfully recovered the stuck pixels.
Key Features
- Native Ultra-HD Support - Precision-engineered to support 4K, 5K, and 8K resolutions, ensuring edge-to-edge coverage on high-density panels.
- OLED Recovery Logic - Specialized rapid-cycle flickering mode designed to "wake up" sub-pixels that have become unresponsive or frozen.
- Universal Touch Control - Seamless gesture-based navigation optimized for iPhone, iPad, and Android mobile browsers.
- Sub-Pixel Analysis - Includes individual Red, Green, and Blue channels to identify specific sub-pixel failures often missed by white-light tests.
- Zero-Latency Performance - Lightweight JavaScript engine renders colors instantly with no server-side lag or data processing required.
- Secure & Anonymous - All diagnostic processes occur locally in your browser memory; no personal hardware data is ever collected or stored.
Common Use Cases
- New Device Validation - Inspecting a newly purchased laptop, monitor, or smartphone for factory defects during the return window.
- OLED Maintenance - Running regular color cycles to help prevent image retention and keep organic sub-pixels active.
- Second-Hand Hardware Appraisal - Checking the screen health of used electronics before finalizing a purchase or sale.
- Professional Calibration Prep - Ensuring a perfectly clean, defect-free canvas before beginning professional color grading or design work.
- Stuck Pixel Recovery - Attempting to fix "hot" or "stuck" pixels that appear as constant bright dots on dark backgrounds.
Frequently Asked Questions
What is the difference between a dead and a stuck pixel?
A dead pixel is permanently off (appears black), while a stuck pixel is frozen on a specific color and can often be fixed with rapid flickering.
How long should I run the Stuck Pixel Fixer?
For best results, we recommend running the fixer for 20 to 30 minutes, though some pixels may take longer to respond.
Is this tool safe for my OLED or HDR screen?
Yes, it is designed to be safe. However, avoid running high-brightness flickering for hours on end to prevent excessive heat.
Does this work on mobile devices?
Absolutely. The tool is fully responsive and supports fullscreen API on most modern iOS and Android browsers.
Can a completely black pixel be fixed?
Generally, no. A black pixel usually indicates a transistor failure (dead), which is a hardware issue that software cannot repair.
Why do I need to test on different colors?
Some pixels only fail on specific sub-pixel levels (e.g., only the green part is broken), which only shows up on certain background colors.
Advanced Tips
- Optimize Room Lighting - Perform the test in a dim or dark room to make faint "hot pixels" and light bleed more visible.
- Identify Backlight Bleed - Use the black color test in a dark room to check for uneven light distribution along the edges of LCD/LED panels.
- Use Physical Pressure - For stubborn stuck pixels, some professionals suggest applying very light pressure with a soft cloth during the flickering cycle (at your own risk).
- Verify Refresh Rate - Ensure your monitor is set to its highest native refresh rate before testing to ensure pixel response times are accurate.
- Check Sub-Pixel Geometry - High-resolution displays have different sub-pixel layouts; use the RGB tests to confirm the consistency of your specific panel type.
- Document for Warranty - If you find multiple defects, take high-macro photos of the screen during the test to provide evidence for manufacturer warranty claims.