Screen and browser window
The logical screen size describes the screen coordinate space exposed to the browser. The viewport describes the area currently available to this page. Browser controls, window size and on-screen interfaces can make the viewport smaller. Resize the window and compare both readings to see the distinction directly.
Device pixel ratio
DPR expresses a relationship between device pixels and CSS pixels. Multiplying logical dimensions by DPR gives a useful estimate, but operating-system scaling, browser zoom and display arrangements affect the reported values. Confirm a panel's native resolution in its documentation or system settings rather than treating that estimate as a hardware specification.
Capability hints
Color-gamut and dynamic-range media queries describe what the browser reports for its current rendering environment. They do not measure gamut coverage, peak brightness or calibrated color accuracy. Use the detailed view to understand the available hints, then open the corresponding visual pattern if you want to inspect the result.