ScreenSize.net

ScreenSize.net instantly displays your screen resolution, viewport size, device pixel ratio, and other live browser-reported values. As you resize the window, all numbers update in real time, and you can copy a full debug report or share a link to paste into a bug ticket.

It clarifies the difference between the physical display size, the full pixel grid, and the CSS viewport where media queries apply, which helps when debugging responsive layouts or adjusting image sharpness and asset sizing. The detection runs entirely in the browser, and only anonymous aggregate stats are stored—no raw visits, IP addresses, or report links are kept on the servers.