Polypane

Polypane is a browser for developers and designers with tons of features that help you build websites that are responsive, accessible and of high quality. Key features * Multi-Viewport Display: Visualize your website across multiple viewports simultaneously, referred to as "panes" in Polypane. * Easy Pane Management: Easily manage panes by adding, removing, and resizing them according to your needs. Customize their behavior based on CSS breakpoints, device presets, or create completely freeform panes. * Synced Interactions: Seamlessly interact with all viewports, ensuring synchronized scrolling, hovering, and form input for efficient testing. * Versatile layouts Options: Choose from horizontal, vertical, or focus layouts to tailor your workspace. Switch to the Full layout for a more traditional browsing experience. * Enhanced Testing Tools: Access a variety of tools, including image overlay and media query emulation, to streamline your testing process.