Polypane. The browser for web developers

For developers, designers, QA and marketers looking to improve their workflow.
Polypane 31 has a new Canvas layout, many improvements to the elements panel, new iPhone presets and Chromium 155.
Polypane 30.1 adds selector specificity highlighting to the elements panel, a new server-sent HTML view in the sources panel, passkey support in Linux and a bunch of improvements and fixes
Polypane 30 introduces Playgrounds so you can open directories as real HTTPS URLs in seconds, adds support for the Side Panel extension API, brings major Network panel improvements, and includes a fully rewritten video recording implementation
Polypane has everything a browser has, plus all the tools you need to ship responsive, fast, accessible, and SEO-friendly websites and apps.Build the way you already build with Polypane as your browser, and find and fix issues as you go.
Polypane is the (Chromium-based) browser devs use to build sites. Check your site continuously as you build, so you find issues as they happen instead of at QA or in production.
Mobile to 5K. Every breakpoint visible and synchronized.
Structure, metadata, accessibility. Instant feedback while you work.
Dark mode, light mode, high contrast, reduced motion. All visible 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.
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.
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.
Synced interactions docs
Share your local development environment anywhere, on any browser, on any device. No tunneling setup, no deployment needed.
Polypane Portal syncs everything to external browsers: scroll position, interactions, style edits and layout debugging. Build in Polypane, test on the real thing.
Your site is more than just its visuals. Polypane has over 40 different debug tools and simulators to help you with every aspect.
Test your site in completely new ways, never miss an issue again.
Check out our Debug tools and Simulators.
Up-to-date previews of social media cards for X/Twitter, Facebook, Slack, LinkedIn, Discord, Telegram, Bluesky, Threads, WhatsApp and Google Search.
Pixel-perfect rendered in dark and light mode. Even with your localhost. Fix typos before they're shared out.
Deep dive into our social media previews
Here's what they say:
Polypane is easily one of the most useful tools for modern web designers and developers.
It is convenient seeing your work in multiple responsive views at the same time. Love it, 💯
This thing is FAST and the synchronized scrolling works amazingly. Prepare to be impressed.
Polypane is really saving my bacon. Kilian knocked it out of the park, this is my new favorite development tool.
If you’re designing modern applications and websites, you should try Polypane! It’s worth every penny!
I've started playing around with Polypane and 🤯. It has awesome debugging tools, accessibility checks and tests, and more. I'm really impressed.
Read more testimonials Join our Slack community
No need to flip your entire operating system! Test light and dark mode side-by-side in the same view.
Also works for reduced motion, reduced data, prefers-contrast, forced-colors and even print styles.
Media emulation docs
Polypane has everything you need to make awesome web experiences.
Polypane replaces your patchwork of tools with a single, powerful browser designed for building better websites. Once you try it, you'll never want to go back.
Frustration. Inefficiency. Blind spots.
Clarity. Speed. Confidence.
Constantly resizing your window or dragging dev tools around.