Open Source Alternatives to Polypane

A Chromium-based web browser for developers that allows for the simultaneous viewing and interaction of multiple synchronized viewports. The software provides tools for responsive design testing across various breakpoints from mobile to 5K resolutions, including built-in accessibility auditing for contrast checks and focus order. It enables developers to emulate different device behaviors, preview meta information and social cards, and test various display modes such as dark mode, light mode, and high contrast side by side. The tool is deployed as a desktop application used to identify layout and accessibility issues during the development process. It replaces the need for multiple browser extensions by integrating meta previews, live reloading, and image overlays into a single interface. This environment is designed for freelancers and teams to ensure a unified testing experience across different screen sizes and accessibility requirements.

Whether you want to cut software costs or escape vendor lock-in, these open source alternatives to Polypane give you an option you fully own. They run locally on your own device, so your data never leaves your machine. This page lists 1 open source alternative to Polypane. The most popular is Responsively App. It uses the AGPL-3.0 license.