What Is My Screen Resolution?
Your screen resolution, browser viewport, and device pixel ratio — live, updated as you resize.
Resize your browser window to see the viewport values update in real time. All detection happens locally in your browser — nothing is sent anywhere.
How screen resolution detection works
Screen resolution is the total number of physical pixels your monitor or display renders, reported by the browser via window.screen.width and window.screen.height. This is different from your browser's viewport (window.innerWidth / innerHeight), which is only the visible page area inside the browser chrome — smaller than the full screen once you subtract toolbars, tabs, and the taskbar.
The Device Pixel Ratio (DPR) bridges CSS pixels and physical pixels: on a standard 1x display, one CSS pixel equals one physical pixel, while on Retina/HiDPI displays the DPR is typically 2x or 3x, meaning each CSS pixel is drawn using 4 or 9 physical pixels respectively. Multiplying the viewport size by the DPR gives the actual physical pixel count the browser is rendering — useful when exporting pixel-perfect screenshots or serving correctly sized responsive images.
Color depth reports how many bits are used per pixel to represent color — 24-bit (16.7 million colors) is standard on virtually all modern displays. All of this data is read directly from your browser's screen and window objects; nothing is uploaded or logged, which is why the values update instantly and only in your own browser session.
Private & free — this tool runs entirely in your browser.