Viewport Inspector — Free, No Upload, Browser-Based

Viewport Inspector shows your browser window's exact width, height, device pixel ratio, and the active Tailwind CSS breakpoint — all updated live as you resize. Everything runs entirely in your browser: no data is sent to any server and no file is ever uploaded. Open it on any device to instantly check responsive breakpoints or share the copied summary with your team.

このツールの使い方

1. Open the tool in your browser on any device or screen size.
2. Resize the browser window and watch the viewport dimensions, device pixel ratio, and active CSS breakpoint update in real time.
3. Click "Copy all viewport info" to copy a one-line summary to your clipboard for sharing or debugging.