Viewport Checker

Viewport Checker is a free, instant, browser-based tool that check your current viewport size and device pixel ratio. Web developer tools provide quick access to reference data and small utilities that come up constantly during development. HTTP status codes, Unix timestamps, chmod permission calculators, ASCII tables, and similar references are things every web developer looks up regularly. Having them in one place, instantly accessible in your browser, speeds up your workflow significantly.

This tool runs entirely in your browser with no server calls required. Results appear instantly and everything works offline once the page is loaded.

Bookmark this page for quick access during development sessions. Whether you're debugging a 403 vs 401 response, converting a timestamp from a database field, setting file permissions on a Linux server, or checking what ASCII character code 127 corresponds to, having a reliable, distraction-free reference tool cuts down the time you spend looking things up and lets you stay focused on the problem at hand.