Polypane

Polypane is a stand-alone browser designed specifically for ambitious web developers. It offers a comprehensive set of features and tools to help developers build, debug, and test websites more efficiently. With Polypane, developers can easily create responsive designs by viewing their websites across a wide range of devices and screen sizes, from mobile screens to 5K monitors. It provides over 80 accessibility tests, simulators, and debug tools to ensure websites are accessible to all users. Additionally, Polypane offers side-by-side views, allowing users to compare different visual settings without manual switching. It supports various platforms and provides powerful dev tools, including full-height screenshots, device and media query emulation, live-reloading, and more.