What's the Real Difference Between Lo-Fi and Hi-Fi Prototypes in 2026 (And Why AI Builders Are Collapsing It)

For two decades, the prototyping ladder was a trade-off between speed and realism. Lo-fi wireframes were fast but unrealistic; hi-fi mockups were realistic but slow. Teams climbed the ladder stage by stage - paper sketch, then lo-fi wireframe, then hi-fi Figma file, then code - because each stage served a different decision and required a different investment of time. The ladder made sense when hi-fi took weeks to produce. In 2026 it takes hours. AI builders generate navigable, visually complete apps from a prompt, which collapses the classical fidelity gap into a single step.