Polypane 29.0.0 – The missing half of your development environment

Polypane is the development browser for building responsive, fast, accessible, and SEO-friendly websites that work perfectly for everyone.

Use it alongside your editor to preview, debug and test sites across screens, devices, and user conditions. Every scroll, click, and edit is synchronized in all panes at once.

Build, don’t browse.

Chrome, Firefox and Safari are excellent browsers for browsing the web. Polypane is the browser developers use for building websites. It’s a Chromium-powered development browser with tools designed for building responsive, accessible, and high-quality sites.

See every breakpoint

Mobile to 5K. Every breakpoint visible and synchronized.

Catch issues as you build

Structure, metadata, accessibility. Instant feedback while you work.

View everything side by side

Dark mode, light mode, high contrast, reduced motion. All visible at once.

Stop resizing. See everything at once.

Stop the manual resize-refresh-check-fix-resize cycle. Get all your viewports in one overview, no browser resizing needed.

Mobile screens, 5K monitors, all your CSS breakpoints or any size you want.

Emulate everything. Not just screen size.

Polypane goes beyond viewport dimensions. Full device emulation including user agent, touch events, locale, safe area insets and viewports. It’s the most comprehensive emulation available.

Test like you’re on the actual device, without leaving your desk. Only available in Polypane.

One interaction. Every viewport.

Every scroll, click, hover, focus and keystroke syncs across all viewports instantly.

Stop repeating yourself by testing devices one-by-one. Interact once, test it everywhere.