Skip to contentSkip to footer

All the tools you need to Build, Debug and Test sites

Powerful dev tools, multiple synced viewports, full-height screenshots, over two dozen debug tools, device and media query emulation, built-in live-reloading and more.

Responsive design

Mobile screens to 5K monitors, see all viewports in one overview.


Over 80 accessibility tests, 19 different simulators and 20+ debug tools.

Side by side views

Dark and light, reduced motion, screen and print. No more manual switching!

Multiple panes

Never resize your browser again

Emulate real devices, use your responsive CSS breakpoints or pick your own dimensions. No resizing needed.

Synced panes

Syncs all your interactions

Your keyboard and mouse interactions are synced between all viewports. Scrolling, hovers, clicks and form input, you only need to do it once.


Device emulation, without the hassle

Emulate popular devices with a single click. Touch emulation, toggle network conditions, switch between light and dark modes on the fly and send custom headers for each pane.

Cross-browser and Cross-device

Other browser invited.

Share your local development environment anywhere, on any browser, on any device.

Polypane Portal keeps everything in sync whether that's the scroll position, interactions, style edits or layout debugging.


Dark mode media feature testing

Develop your site in light and dark mode at the same time, both in view and synced together. There is no faster way to build sites with dark and light mode.

Make your browser work for you

Element panel & Live CSS panel

Edit all panes at the same time

Make changes to all panes at once using our Elements panel and Live CSS editor. We'll automatically import any Google font you use for quick prototyping.

Browse panel

Documentation on the side

Quickly show documentation or references in the side browser, so you don't have to lose sight of your project. That's right, there's a browser in our browser.

Everything needed to make great web experiences.

Media features

Detect CSS breakpoints

Use the CSS breakpoints in your stylesheets to automatically generate viewports for every view your site supports.

Chromium devtools

Your favorite DevTools extensions

Install and use your favorite devtools, with support for React DevTools, Vue.js DevTools, Redux DevTools, Angular, Svelte and many more.

zero configuration

Intelligent Live and Hot reloading
For everyone

Live reloading for any development environment, from plain HTML to Wordpress to React or Vue. CSS and images even update without a page refresh.

Debugging an issue becomes quick and easy

Debug tools

Custom debug tools for each pane

Over forty debug tools let you easily check contrast and accessibility, edit your page visually and get insights into your page structure.

Meta panel

Social media previews and meta info


Live previews of how your site looks when shared on social media. All your meta information is visible so you catch typos and missing info in a glance.

Deep dive into our social media previews

Outline panel

Let your browser tell you which links are broken.

Polypane automatically checks all the links on your page and if they're broken, redirect or have referrer issues, we'll let you know.

Reference image

Build pixel perfect sites

Compare an image with the expected design to your live site with different comparison modes built right in.

* We don't think sites have to be pixel perfect. But getting close is nice.

Testing takes minutes instead of days

Debug tools

See like your users do

Test your website with many different visual impairment simulators, like color blindness and cataracts but also situational impairments like bright sunlight or devices with night mode.


Full page screenshots

You want best in class screenshots, and we have them. No other browser comes close in terms of rendering accuracy. We also support screenshots of all your viewports.

Compare full page screenshots

Plays well with all your favorite frameworks.

Devtools extensions for your favorite JS frameworks and easy ways to prototype with your favorite CSS frameworks. Keep your stack, be more productive.

  • React
  • Vue
  • Angular
  • Svelte
  • jQuery
  • Tailwind CSS
  • Bootstrap
  • Foundation
  • Bulma

And much more

Unlimited Viewports
Scroll Syncing
Hover Syncing
Grid Overlays
Unified Console
Keyboard Syncing
JSON Viewer
Device Presets
Freeform Resizing
Horizontal Overflow Detection
Developer Tools
Pixel-perfect Social Media Previews
Different Layout Modes
Device Emulation
Handoff Support
Live Reloading
Accessibility Audits
Custom Sessions
Page Outlines
Live CSS Editing
Color Blindness Simulators
Full Page Screenshots
Visual Design Diffing
Meta Data Overview
CSS Breakpoint Detection
Overview Screenshots
Unified Element Inspector
Touch Emulation
Automated Form Testing
Screenshot Editor
Web Vitals Inspector
Color Picker
Browser Extensions
Broken Link Checking
Share Links
Custom Headers
Dark Mode
…and more added monthly!
User testimonials

Developers and designers love Polypane.

Here's what they say:

Polypane is easily one of the most useful tools for modern web designers and developers.

Stephen Hay Author of Responsive Design Workflow

It is convenient seeing your work in multiple responsive views at the same time. Love it, 💯

Sara Soueidan Independent front-end UI engineer, Speaker/Trainer

This thing is FAST and the synchronized scrolling works amazingly. Prepare to be impressed.

Vivian Guillen Frontend Developer & Curator at Tailwind Weekly

Polypane is fast, helps me catch issues and the meta information preview is awesome.

Graeme Fulton Founder at Letter

Using Polypane and woah this is awesome! It’s really slick and fast! I was just 5 minutes in and I already fixed a bug.

Sergio Mattei Founder at Makerlog

I've started playing around with Polypane and 🤯. It has awesome debugging tools, accessibility checks and tests, and more. I'm really impressed.

Kevin Powell CSS Evangelist

Read more testimonials

Build your next project with Polypane

  • Use all features on all plans
  • On Mac, Window and Linux
  • 14-day free trial – no credit card needed
Try for free
Polypane screenshot