No need to reload layouts to view pages at different sizes. Synchronized browsing: Navigating in either pane updates the other.

Whether you're a designer or a developer, project manager or client, Duo gives you a new tool to make your Responsive Web Design project go more smoothly than ever.

By seeing these two views at the same time, you're able to quickly test and work through multiple screen experiences rather than considering them separately. Duo is a dual-paned web browser that lets you browse the web in two views: your standard 'desktop' view as well as a typical 'mobile' view.