Low-Fidelity Prototype (Lo-Fi)

A Low-Fidelity Prototype (Lo-Fi) is a basic, non-interactive version of a product or feature created to test the structure and functionality. Lo-Fi prototypes are typically made using sketches, wireframes, or paper models and are useful for rapid ideation and feedback collection. They help teams visualize concepts and test user flows with minimal investment in design or development.

Lo-fi prototypes are the fastest way to explore and discard ideas before investing in execution — you can test 5 different navigation structures in an afternoon with paper sketches in a way that would take weeks in code. The deliberate roughness also signals to users in testing that the design is not precious, making them more likely to give honest critical feedback rather than politely approving something they sense took effort.

Amazon's product teams are required to write a 'working backwards' press release before building anything, but some teams additionally create paper prototypes of key flows — this low-tech, high-speed approach lets them validate assumptions before any design or engineering time is committed.