Online Screen Test · Professional Monitor Testing Tool | Dead Pixel, Backlight Bleed, Color Accuracy & Burn-in Detection

An online screen test is a diagnostic tool designed to evaluate the quality and performance of your monitor or display. Whether you're setting up a new monitor, checking a laptop screen test online, or troubleshooting display issues, this tool uses standardized patterns to reveal imperfections invisible to the naked eye during daily use. From dead pixel test to backlight bleed test, it provides a complete assessment of your display's health.

This monitor test tool supports 27 professional testing modes, covering everything from basic dead pixel detection to advanced color accuracy test and gradient performance. All tests run locally in your browser—no downloads, no plugins, no internet required—providing instant, reliable results.

Step 1: Enter Test Mode — Click the green "Start Monitor Test" button in the center of the page. The tool will automatically switch to full-screen testing mode for the most accurate results.

Step 2: Navigate Through Tests — We recommend this sequence for a comprehensive screen check:

• Solid Color Tests (Red→Green→Blue→Yellow→Cyan→Magenta→White→Black) — Detect dead pixels, stuck pixels, and dark spots
• Line Pattern Tests (Horizontal→Vertical→Diagonal→Dot Matrix) — Check for signal interference and image stability
• Pattern Tests (Micro Pattern→Flashing Squares→Square Grid→Color Grid) — Evaluate focus, breathing effect, and geometric distortion
• Contrast Tests (Dark Contrast→Bright Contrast) — Assess your display's grayscale performance
• Gradient Tests (White→Red→Green→Blue) — Check color transition smoothness and detect banding
• Saturation Test — Evaluate color saturation performance

Step 3: Observe and Judge Display Quality — Look closely at each pattern: are there any bright or dark pixels (dead pixels)? Is there light bleeding from the edges? Are lines perfectly straight? Do color gradients transition smoothly? Can you distinguish the edge of each contrast block?

Step 4: Exit the Test — Press the ESC key or click the close button in the control panel to return to the welcome page.

Ambient Lighting: For best results, especially for a backlight bleed test or contrast evaluation, test in a dim or dark room. Strong ambient light can mask subtle issues like screen bleeding.

Viewing Distance: Maintain your normal viewing distance (about 50-70cm). If you spot a potential pixel defect, move closer to confirm.

Dead Pixel Standards: Industry standards often allow 3-5 dead pixels per million pixels, but high-end monitors should aim for zero. Solid red, green, blue, white, and black screens make dead pixel check easiest.

Backlight Bleed: Minor light bleeding on IPS panels is normal. However, large areas or unusually bright corners may indicate a quality control issue.

Contrast Test: On the dark contrast page, non-professional monitors often struggle to distinguish the last row of blocks. On the bright contrast page, standard monitors may struggle with the first row.

Gradient Test: A high-quality display shows smooth, seamless transitions. Budget monitors may exhibit visible color banding or streaks.

Grid/Line Tests: If lines aren't perfectly straight, use your monitor's OSD menu to adjust the picture position and size.

What is a dead pixel? A dead pixel is a pixel that remains permanently unlit (black) or permanently lit (white/stuck). This monitor pixel test displays solid colors to help you spot them easily.

How can I test my laptop screen for bleeding? Use the solid black pattern in a dark room. Backlight bleed appears as uneven bright areas, typically along the edges. This is a critical step in any LCD screen test.

Can this tool help with color calibration? While this is primarily a display test tool, the gradient and contrast patterns can visually indicate if your monitor's color calibration is severely off. For precise work, hardware calibration devices are recommended alongside a color accuracy test like Lagom.

Is this screen test online tool secure? Yes. The entire test runs locally in your browser. No data is sent to any server, ensuring your privacy is completely protected during the online monitor test.

Does this test work for OLED screens? Yes. An OLED screen test benefits particularly from the solid black and white patterns, which can highlight the perfect black levels and uniformity of OLED technology, as well as potential burn-in.

How often should I run a screen check? Perform a display check online when you first purchase a new monitor, after transporting a laptop, or any time you notice visual anomalies like flickering or color shifts.