Display resolution checker
What Is My Screen Resolution? Free Live Checker
Instantly read your display's screen.width and screen.height in CSS pixels, compare with your browser viewport, and see estimated physical pixel dimensions.
What is screen resolution?
Screen resolution is the width and height of your display in pixels. In the browser, screen.width and screen.height report CSS pixels — logical units that may differ from the panel's physical pixel count when devicePixelRatio is greater than 1.
screen.width
Total display width in CSS pixels — usually fixed for a given monitor or device.
Physical pixels
Approximate native count: screen dimensions × devicePixelRatio.
innerWidth
Browser viewport — often smaller than screen when the window isn't fullscreen.
Screen resolution vs viewport
Developers often confuse screen size with viewport size. Screen resolution describes the display; viewport describes the layout area inside your browser window. Use the viewport checker for responsive layout, the DPR checker for retina scaling, and our viewport vs screen vs DPR guide for JavaScript snippets.