How PPI is calculated:
PPI = sqrt(width² + height²) / diagonal inches. Higher PPI means sharper text and images. Retina displays (Apple standard) are 326+ PPI for phones and 220+ PPI for monitors.
Free online PPI calculator to compute pixel density for any display. Enter screen resolution and diagonal size to calculate PPI (pixels per inch), megapixels, and aspect ratio. Includes common presets for monitors, laptops, phones, and tablets. Compare pixel density across devices to understand display sharpness. Works on all devices — no download required.
Free online dead pixel tester for monitors, laptops, phones, and tablets. Display full-screen solid colors (white, black, red, green, blue, yellow, cyan, magenta) to detect dead pixels, stuck pixels, and screen defects. Test new monitors within return window, check used devices before buying, and diagnose display issues. Works on all devices with a modern browser — no download required. All testing runs locally in your browser for 100% privacy.
Free online screen color test to check monitor quality. Test color gradients for banding, check brightness uniformity across the screen, calibrate gamma, compare two colors side by side, and test text sharpness. Includes grayscale gradient, RGB gradient, and custom gradient tests. Works on all monitors, laptops, and phones — no download required. All testing runs locally in your browser for 100% privacy.
