Proto IO

Proto.io is a browser-based prototyping platform for designing and testing interactive web and mobile experiences without writing code. It enables product teams, UX/UI designers, and stakeholders to create low- to high-fidelity prototypes that closely mimic real applications across web, iOS, Android, and other platforms. Users can drag and drop pre-built, customizable UI components, templates, and icon libraries to quickly assemble screens and flows, then refine them with detailed interactions, animations, and transitions.

The tool supports advanced interaction design, including gestures, micro-interactions, multi-screen flows, and conditional logic, allowing realistic simulations of user journeys. Prototypes can be previewed in the browser or on actual devices, helping teams validate usability, navigation, and content hierarchy before development. Collaboration features typically include sharing interactive prototypes via links, gathering comments, and iterating based on stakeholder or user feedback.