Screen Tester
Select a test pattern below to diagnose your display.
Click Fullscreen for accurate dead pixel, backlight bleed, and uniformity testing. Sub-options appear per pattern.
What Does Screen Tester Check?
A screen tester is a diagnostic tool that evaluates your monitor or display’s performance and quality. This tool uses your browser’s Canvas API to generate standardized test patterns that help you identify color accuracy issues, dead pixels, and display uniformity problems. The screen tester displays various visual patterns including solid colors, gradients, grids, and geometric shapes to thoroughly assess your display’s rendering capabilities. By running these tests, you can detect pixel defects, color banding, distortion, and other visual anomalies that might indicate hardware problems or performance degradation in your monitor.
Supported Devices
This screen tester works on virtually any device with a modern web browser, including desktop monitors, laptop screens, tablets, and smartphones. It supports all major display types including LCD, LED, OLED, and IPS panels across Windows, macOS, Linux, iOS, and Android operating systems. Whether you’re testing a gaming monitor, professional display, tablet screen, or mobile phone display, this tool adapts to your device’s resolution and provides accurate diagnostics. The tool is compatible with Chrome, Firefox, Safari, and Edge browsers, ensuring broad compatibility across different hardware platforms and screen sizes.
How To Use This Tool
Using the screen tester is straightforward and requires no special setup or equipment. Simply open the tool in your web browser and select one of the six test patterns from the buttons above the canvas area. Each pattern is designed to test different aspects of your display, so run through all of them to get a complete picture of your monitor’s health. Watch carefully for any visual artifacts, color shifts, dead pixels, or distortions as each pattern displays. Take note of any issues you observe, particularly in the focus areas test which highlights corner and center regions where problems often appear first.
Understanding Your Results
When reviewing your screen test results, look for consistency in color reproduction across the solid color patterns and smooth transitions in the gradient tests. The grid pattern should display perfectly straight lines without any warping or distortion, while geometric shapes should have clean, sharp edges. Pay special attention to the focus areas test, which checks corner visibility and center accuracy where many display defects concentrate. If you notice dead pixels, color banding, dark spots, or geometric distortion during any test, your display may need professional servicing or replacement depending on severity.
Frequently Asked Questions
Q: Why does my screen show dead pixels in the test?
A: Dead pixels appear as dark spots that don’t respond to color changes. This indicates a hardware fault in your display panel that typically requires professional repair or monitor replacement.
Q: Can I fix color banding issues detected by the screen tester?
A: Color banding usually indicates a display panel limitation rather than a fixable software issue. You may be able to adjust color settings in your monitor’s menu, but significant banding typically means upgrading to a higher quality display.
Q: Does the screen tester work on mobile phones?
A: Yes, the screen tester works on any device with a web browser, including smartphones and tablets. It automatically adapts to your device’s screen size and resolution.
Q: What does the focus areas test reveal?
A: The focus areas test checks the corners and center of your display for edge visibility problems, brightness inconsistencies, and color accuracy issues that commonly appear in these regions.
Q: How often should I run the screen tester?
A: Run the screen tester periodically if you suspect display problems, or once when you first get a new monitor to establish a baseline for its condition and performance.
Q: Why are gradients important in display testing?
A: Gradients reveal color banding and smooth color transition capability in your display. Poor gradient rendering indicates limited color depth or panel quality issues that affect image quality.