Check your monitor, laptop, smartphone, or TV display for dead pixels, stuck pixels, hot pixels, bright pixels, and dark dots with our free online Dead Pixel Tester. Includes a built-in pixel fixer that rapidly flashes colors to revive stuck pixels — no downloads, no installation, 100% free.
The Pixel Fix mode rapidly flashes colors at high frequency. Do not look directly at the screen during fix mode if you have photosensitive epilepsy or are sensitive to flashing lights. Move the browser window away, or close your eyes during the fix cycle.
A Dead Pixel Test (also called a Pixel Checker, Stuck Pixel Test, Monitor Pixel Test, or Screen Defect Tester) is a quick visual diagnostic that reveals whether any individual pixels on your display are malfunctioning. By filling your screen with pure solid colors, the test makes non-functioning pixels instantly visible as tiny black dots, colored specks, or bright spots against the uniform background.
Our free online Dead Pixel Tester combines a complete pixel diagnostic suite in one browser-based tool. It includes 12 solid test colors, gradient and checkerboard patterns, and a built-in Pixel Fixer that uses rapid color cycling to potentially revive stuck pixels. The tool works on any device with a modern browser — monitors, laptops, smartphones, tablets, and smart TVs.
Whether you're checking a brand-new monitor within the return window, inspecting a used display before purchase, or trying to revive a stuck pixel on your smartphone, this pixel checker and fixer is the same tool used by professional reviewers and quality-control specialists — available free in your browser.
These three pixel defects look similar but have completely different causes — and only some are fixable. Identifying the type first is essential.
A complete pixel check takes less than 5 minutes. Follow these steps for the most reliable detection of every type of pixel defect.
Wipe the display with a microfiber cloth first. Dust, lint, and fingerprints easily look like dead pixels — a clean screen prevents false positives.
Click the Fullscreen button to hide browser UI and taskbar. Testing in fullscreen mode is essential to check 100% of your display area.
Increase display brightness to maximum. Brighter backgrounds make dead pixels dramatically more visible, especially on white and primary colors.
Test white, black, red, green, blue at minimum. Different defects only show on specific colors — black reveals hot pixels, white reveals dead pixels.
Scan the entire screen systematically — top to bottom, left to right. Pay extra attention to center area where defects matter most for warranty claims.
If you find stuck pixels, run the Pixel Fixer for 20-30 minutes. Cover the affected area with the flashing pattern to attempt automatic recovery.
Our Dead Pixel Test works by rendering pure, single-color images directly to your browser's canvas at native pixel resolution. No compression, no image scaling, no rendering shortcuts — each pixel on your screen is asked to produce the exact target color. Any pixel that fails to reproduce the color correctly becomes immediately visible as a contrasting spot.
A modern display is built from millions of individual pixels, each containing three sub-pixels — red, green, and blue. When all three sub-pixels work correctly, they combine to produce the intended color. When one or more sub-pixels fail, the pixel displays the wrong color entirely, creating the defect you see during testing.
The Pixel Fixer mode uses a scientifically-proven technique: rapid color cycling. By flashing red, green, blue, white, and black at high frequency, the tool forces each sub-pixel to rapidly switch between fully-on and fully-off states. This electrical stimulation can "exercise" stuck sub-pixels and sometimes restore normal function. Dead pixels cannot be fixed — they have no electrical signal at all — but stuck pixels have a 50–80% chance of recovery with 20–30 minutes of treatment.
All testing happens locally in your browser. No data, pixel counts, or test results are ever transmitted to any server. The entire tool works offline after the initial page load.
Understanding why pixels fail helps you decide between warranty claims, fixer attempts, or acceptance.
Millions of sub-pixel transistors are etched onto every display. Random manufacturing flaws cause some transistors to be DOA from the factory.
Dropping, pressing hard on, or sitting on a display can crush liquid crystals or damage transistor connections at the impact site.
Leaving a device in hot cars, direct sunlight, or freezing conditions damages the liquid crystals and creates permanent dead or stuck pixels.
Power spikes can burn out individual transistors, causing pixels to die. Use surge protectors to prevent this on expensive displays.
Moisture entering the display can short-circuit sub-pixels or damage liquid crystal alignment, producing stuck or hot pixels.
After years of use, transistors naturally age and fail. Dead pixels are more common on older displays and some gradually appear over time.
Several proven methods exist for reviving stuck pixels. Start with the least invasive and work up only if needed.
Run our Pixel Fixer mode in fullscreen for 20-30 minutes. Rapid color cycling electrically exercises stuck sub-pixels. Safest method with 50-80% success rate.
Turn screen off. Place soft cloth over stuck pixel. Apply gentle, consistent pressure for 5-10 seconds. Turn screen back on. Risky — can scratch or damage panel.
With screen displaying the stuck area as black, gently tap the pixel with a soft object (like a pencil eraser). Can realign liquid crystals but risks damage.
Power off the display for 24 hours. Recently-stuck pixels sometimes resolve themselves when electrical charge dissipates. Zero-risk approach.
Most manufacturers replace units with 3+ dead pixels or 1 in the center. Use our tool to document. Dell, Apple, LG have strict zero-defect policies.
Apply warmth (a warm damp cloth) to the stuck area briefly. Heat can loosen liquid crystals. Only for experienced users — too much heat damages panels.
Run fixer for 30 minutes, then switch to pressure method, then run fixer again. Stubborn stuck pixels sometimes need multiple combined approaches.
If within ISO tolerance (usually 3-5 pixels acceptable), manufacturers won't replace. Consider if the defect actually affects your daily use before spending.
Quick answers to the most common questions about testing, fixing, and diagnosing pixel defects on any display.