Polypane

About

Polypane is a Chromium-based browser for web developers. It lets you see every breakpoint, from mobile to 5K, in one synchronized overview, so you don't need to resize your browser. Its device emulation goes beyond screen size to include user agent, touch events, locale, safe area insets, and viewports. Scrolling, clicks, hover, focus, and keystrokes sync across all viewports, and you can test light and dark mode, reduced motion, and other user preferences side by side.

Polypane also includes over 40 debug tools and simulators for checking structure, metadata, accessibility, and layout as you work. Its Meta panel previews social media share cards for services such as X/Twitter, Facebook, Slack, LinkedIn, and Google Search, including localhost. Polypane Portal syncs your local development environment to external browsers and devices, with no tunneling setup or deployment required.

Polypane offers a free 14-day trial, and no credit card is needed to start.