The numbers update when you resize the browser, rotate the device, change zoom or move the window between displays. Screen size tells you the CSS-pixel size reported by the display, viewport size tells you the space available to the web page, and device pixel ratio explains how many physical pixels map to one CSS pixel. Together they help you debug responsive layouts, screenshots, media queries and display-specific bugs.
Screen Resolution Detector
Runs entirely in your browser - no upload, no sign-up.
What is a screen resolution detector?
A screen resolution detector reads the display facts your browser can see: screen width and height, available screen area, current viewport size, device pixel ratio, estimated physical pixels, orientation, color depth, touch support and media-query capabilities. This tool shows those values instantly in your browser without uploading anything.
FAQ
Is this screen resolution detector free?
Yes. It is free to use, with no sign-up and no usage limit.
Does it upload my screen information?
No. The detector only reads browser APIs on your device. Nothing is uploaded or stored on a server.
What is the difference between screen size and viewport size?
Screen size is the display size reported by the browser. Viewport size is the area the web page can currently use inside the browser window, so it changes when you resize the window, open sidebars or rotate a phone.
What is device pixel ratio?
Device pixel ratio, often shortened to DPR, is how many physical display pixels are used for one CSS pixel. Browser zoom, OS scaling and external displays can change it.