Fluid UI

Fluid UI is a browser-based prototyping tool that helps designers, product managers, and developers quickly turn ideas into interactive web and mobile prototypes. It addresses the challenge of communicating a product vision clearly by allowing users to create shareable, clickable prototypes that bridge the gap between what is in someone’s mind and what others understand.

Key capabilities include built-in component libraries for Material Design, iOS, Windows, and wireframing, along with support for uploading existing assets. Users can add interactivity through mouse and touch gestures, page animations, and a screenflow diagram that shows how pages relate. Real-time collaboration lets teams work on the same prototype simultaneously, with live video calling, page locking, and a reviewer mode for comments and annotations. The tool works in browsers, has an installable desktop client, and offers free preview apps for Android and iOS.

Fluid UI is aimed at designers, entrepreneurs, developers, product managers, and educators. A free lifetime account is available, with paid Solo, Pro, and Team plans that offer increasing numbers of active projects, user licenses, and features such as export, print, comments, and real-time team collaboration. Plans can be billed monthly or annually, and educational and non-profit discounts are available on request.