My Screen Resolution

Reports every number that answers 'what resolution am I actually looking at' — screen resolution, browser window size, device pixel ratio and colour depth — updating live as the window is resized, rather than showing a single static figure that may not match what a web page can actually use.

Screen resolution vs browser window size

Screen resolution is the full physical display — the number a monitor or laptop is sold with. Browser window size is smaller: it's the screen resolution minus the browser's own chrome (tabs, address bar, bookmarks bar) and any OS taskbar or dock. A 1920×1080 screen commonly leaves a browser viewport closer to 1920×950 once that chrome is subtracted — and CSS media queries, used for responsive web design, respond to the window size, not the screen size, which is why this distinction matters for anyone testing a website's breakpoints.

Device pixel ratio and physical pixels

A 'Retina' or high-DPI display packs more physical pixels into the same space than a standard display, and reports itself to web pages using a smaller logical resolution multiplied by a device pixel ratio — commonly 2 or 3 on modern phones. Multiplying the reported resolution by the pixel ratio gives the true physical pixel count, which matters for anyone exporting images or icons at native display resolution.