The best UX prototyping tool for modern workflows is generally considered to be Figma, because it offers an excellent balance of usability, real-time collaboration, and advanced prototyping capabilities in a single cloud-based platform. It allows designers to create interactive prototypes quickly with drag-and-drop simplicity while also supporting high-fidelity interactions, animations, and user flow testing without needing additional software. Its strongest advantage is real-time collaboration, where multiple designers, developers, and stakeholders can work on the same file simultaneously, making feedback and iteration much faster. Tools like Adobe XD and Framer also provide strong prototyping features, especially for motion design and advanced interactions, but Figma stands out because it is easier to use, highly collaborative, and widely adopted across design and development teams.