What Is My Screen Size?

WhatIsMyScreenSize.com is a comprehensive online resource for understanding and comparing display technology. The site automatically detects your device's screen size, resolution, aspect ratio, pixel density (PPI), refresh rate, and other display characteristics directly in your browser, without collecting or storing personal data. Beyond simple screen detection, the platform includes a growing collection of tools for developers, designers, and technology enthusiasts, including viewport checkers, media query generators, responsive breakpoint testers, pixel density calculators, monitor scaling calculators, aspect ratio generators, and CSS viewport unit visualizers. These tools make it easy to debug responsive websites, optimize UI layouts, and understand how content renders across different devices. The website also maintains an extensive database of smartphones, tablets, laptops, monitors, and other devices, allowing users to compare screen sizes, resolutions, display technologies, and pixel densities side by side before purchasing. Educational guides explain topics such as Retina displays, device pixel ratio (DPR), CSS pixels, monitor scaling, and choosing the right accessories for different screen sizes, making the site valuable for both professionals and everyday consumers.