Viewpo
Developer Tools for Responsive Design
Check your screen size, explore device viewports, and compare CSS breakpoints — all free, no sign-up required.
Available Tools
My Viewport
What screen size is this?
Instantly see your viewport dimensions, screen resolution, device pixel ratio, colour depth, orientation, and which popular device matches your screen.
Device Viewport Database
Every device, every viewport.
Searchable database of 50+ popular phones, tablets, laptops, and monitors with viewport dimensions, DPR, and CSS breakpoint mappings.
Breakpoint Visualiser
See where devices land.
Compare CSS breakpoints across Tailwind, Bootstrap, and Material UI. See which devices fall into each range with an interactive diagram.
Need a full responsive audit?
These tools check individual aspects. Viewpo audits your entire site — real browser screenshots at every viewport, automated checks, and an A-F grade with specific issues to fix.
Try Viewpo Free