Principle is a macOS‑only animation and interaction design tool for crafting high‑fidelity UI prototypes. If you’re looking for other graphic‑design and prototyping solutions—whether you need cross‑platform support, real‑time collaboration, or a different pricing model—here are 20 strong alternatives.
Get targeted exposure with custom position pinning and highlighted placement.
Web‑based, real‑time collaborative design tool with vector editing, interactive prototyping, and design system management.
Vector‑based UI/UX design app from Adobe, offering repeat grids, voice prototyping, and seamless integration with Creative Cloud.
macOS‑only vector design app focused on UI design, with robust plugin ecosystem and shared libraries for design systems.
Interactive design platform that blends visual design with code (React) for high‑fidelity prototypes and animations.
All‑in‑one screen design, animation, and prototyping tool with advanced motion design and shared design system features.
Powerful wireframing and prototyping suite that supports conditional logic, dynamic content, and detailed documentation.
Free, Facebook‑built prototyping tool for creating complex interactions and animations, especially for mobile UI.
Web‑based platform for building fully interactive mobile prototypes without coding, with extensive UI component libraries.
Simple, browser‑based design, prototyping, and user testing tool that integrates with Sketch and Figma.
Design system‑focused prototyping tool that supports advanced interactions, states, and code‑based components.
Open‑source, web‑based design and prototyping platform with SVG editing, collaborative features, and self‑hosting options.
Low‑fidelity wireframing tool that mimics hand‑drawn sketches, ideal for early‑stage concept validation.
Full‑featured prototyping solution for web and mobile apps, supporting conditional navigation, data integration, and UI kits.
Cross‑platform vector design app (desktop & web) with UI design templates and basic prototyping capabilities.
Professional vector graphics editor with precise control, suitable for UI design and illustration, though prototyping is manual.
Free Windows‑native design tool compatible with Sketch files, offering vector editing, UI kits, and basic prototyping.
Web‑based 3D design and prototyping platform that lets you embed interactive 3D models into UI mockups.
No‑code prototyping app focused on advanced micro‑interactions, sensor data, and conditional logic.
macOS app for creating high‑fidelity interactive prototypes with timeline‑based animation and device preview.
Design‑to‑code plugin for Figma, Sketch, and Adobe XD that turns static designs into responsive, interactive prototypes.