Frequently Asked Questions

ScreenLab is a free collection of 39 browser-based display diagnostic tools. You can test for dead pixels, check OLED burn-in, calibrate colors, measure refresh rates, and more. Everything runs in your browser with zero downloads.

No. All tools run directly in your web browser. Just open a tool and start testing. Works on Chrome, Firefox, Safari, Edge, and most modern browsers.

Yes. Most tools work on smartphones and tablets. Some tools like the touch screen test are specifically designed for mobile devices. For the best dead pixel testing experience, use a desktop monitor in fullscreen mode.

Yes, completely free. We support the site through non-intrusive advertising. All 39 tools are available without registration or payment.

A dead pixel is a pixel whose transistor has permanently failed. It appears as a persistent black dot on your screen that never lights up, regardless of what color is displayed.

Unfortunately, truly dead pixels cannot be fixed with software because the transistor is physically broken. However, stuck pixels (which appear as a colored dot rather than black) can sometimes be fixed using our Stuck Pixel Fixer tool.

Ideally zero. Most premium monitor brands have a zero dead pixel policy. Budget monitors may allow 1-5 dead pixels under warranty. Always test a new monitor within the return window.

OLED burn-in is permanent image retention caused by organic compounds in OLED pixels degrading unevenly. Static elements like taskbars or channel logos can leave permanent ghost images. Our Burn-in Check tool helps you detect early signs.

Reduce brightness, enable pixel shift, auto-hide your taskbar, use dark mode, vary your content, and set reasonable screen timeouts. Read our detailed OLED burn-in prevention guide on the blog.

OLED offers perfect blacks, infinite contrast, and faster response times. LED/LCD typically offers higher peak brightness, no burn-in risk, and longer lifespan. The best choice depends on your use case. Read our OLED vs LED comparison for details.

Use our Color Accuracy tool to compare reference color patches against known sRGB values. For professional work, consider a hardware colorimeter, but our browser-based tools give you a good starting point.

Color banding is usually caused by limited bit depth (6-bit or 8-bit panels), incorrect settings, or a cable that does not support full color depth. Our Gradient Test helps you identify banding issues. Check our Color Banding Fix guide for solutions.

Use our Refresh Rate Test tool. It measures the actual refresh rate your browser is rendering at, which should match your display settings. Common rates are 60Hz, 120Hz, 144Hz, and 240Hz.

Response time is how fast a pixel can change from one color to another. Slower response times cause ghosting and motion blur. Our Motion Blur Test and Response Time tools help you evaluate this.

Pulse Width Modulation (PWM) is a backlight dimming technique that rapidly turns the backlight on and off. At low brightness, this can cause eye strain and headaches for sensitive people. Our PWM Flicker Test helps detect it.

Draw on the canvas to check for dead zones, test multi-touch by placing multiple fingers, and verify touch accuracy. The test works on any touch-enabled device including phones, tablets, and touch monitors.

It measures how quickly you can click after seeing a visual change. Average human reaction time is around 200-250ms. The test helps you benchmark your reflexes and also tests your display input lag.

Partly! The Click Speed Test, Aim Trainer, and Reaction Time tools double as input lag and display response tests. They also help you benchmark your mouse accuracy and speed.