What Is My Viewport Size?
Live innerWidth, innerHeight, visualViewport, and safe-area values in CSS pixels—so you can debug layouts without DevTools.
Reading viewport…
Viewport vs screen resolution
Your screen has a fixed hardware resolution; your viewport is what CSS layouts use—the visible area of the web page, which changes with window size, zoom, and mobile browser chrome.
For hardware resolution and PPI, use our screen size checker or CSS viewport units (vh & dvh).
When you need this tool
- Documenting bugs: "Repro at viewport 390×844 with DPR 3"
- Checking
100vhissues on mobile (pair with the dvh comparison) - Reading
env()safe-area insets for notched devices