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Check your screen for dead, stuck, and bright pixels online to quickly evaluate monitor quality.
Tap 'Start Fullscreen Test' to enter fullscreen mode. The screen will display a solid color background.
Carefully observe the screen for any discolored or unlit pixels (dead pixels).
Tap the screen or use arrow keys to switch colors. We recommend checking each color in order.
Test Colors
Overview
Understand what the tool solves, how it works, and the boundaries of its data.
This page fills the display with one solid color at a time so you can visually inspect the panel for dots that stand out from their surroundings. It cycles through black, white, red, green, blue, cyan, magenta, and yellow. The changing backgrounds provide different visual contrasts; the page does not analyze the screen or produce an automated pass/fail result.
A point that blends into one color may be easier to notice against another. Look at the same physical location as the background changes, and note whether the spot stays in place and which colors make it most visible. The sequence starts with black, then white, red, green, blue, cyan, magenta, and yellow before looping back to black.
ISO/TR 9241-310:2010 summarizes knowledge about pixel-defect visibility and provides guidance on visibility thresholds and aesthetic considerations. ISO states that this technical report does not itself set pixel-defect requirements; the applicable acceptance policy depends on the display and its manufacturer.
Guide
Follow the workflow and verify inputs and outputs with practical examples.
Choose the full-screen test. It opens on a black field.
Scan the center, edges, and corners at a steady pace. Look for a small point that differs from the surrounding color.
Click the screen or press the right arrow or Space to advance. Use the left arrow to revisit a color; the color dots let you jump directly to a specific field.
When a location looks unusual, record its position relative to a corner or screen edge and compare it on several colors.
Press Esc or use the close control to leave the full-screen view.
Keep the scan pattern consistent between colors, such as top edge, middle from left to right, bottom edge, then corners. A repeatable pass makes it easier to check whether you are seeing a stable screen location or a temporary visual distraction.
Use cases
See how the tool fits into real work and everyday tasks.
After setup, cycle through each solid field and inspect the entire panel. If a point catches your eye, revisit the same location on multiple backgrounds before documenting it for the seller or manufacturer.
If a tiny mark appears during normal use, use plain backgrounds to see whether it remains at one panel location. This gives you a consistent visual note to compare during later troubleshooting.
Q&A
Find concise answers to common questions and confusing cases.
No. It displays color fields only. You inspect the screen and keep any notes yourself.
No. It does not measure color accuracy, brightness uniformity, backlight bleed, or refresh rate.
No. A visual spot is a reason to inspect further, not a warranty decision. Check the policy for your exact device model and follow the manufacturer’s review process.
Notes
Review scope, result limitations, and important precautions before use.
The result depends on your visual inspection, display settings, viewing conditions, and whether the full panel is visible. Dust, surface marks, reflections, browser controls, or the surrounding interface can be mistaken for a display issue. Clean the surface and revisit a suspected point across several colors before drawing a conclusion.
This page cannot classify a pixel defect or determine whether a panel meets a manufacturer’s tolerance. ISO/TR 9241-310 offers visibility guidance but does not prescribe defect acceptance limits. Use the device maker’s policy for warranty or return decisions.
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