Prototype
Also known as: interactive prototype, clickable prototype
What Is a Prototype?
A prototype is an interactive model of a product used to simulate user flows, test interactions, and validate design decisions before development begins. Unlike a mockup, which shows how a product looks, a prototype shows how it behaves — buttons respond to clicks, screens transition, and navigation paths can be followed end to end.
What Are the Types of Prototypes?
Prototypes range in fidelity depending on what's being tested.
Low-fidelity prototypes connect wireframe-level screens with basic click interactions. They're quick to build and useful for testing navigation logic and user flows without investing in visual design first.
High-fidelity prototypes are built from finished mockups and simulate the final product closely — including transitions, micro-interactions, and real content. They're used for usability testing, stakeholder presentations, and developer handoffs where interaction behavior needs to be specified precisely.
The choice between them comes down to what questions need answering. Early on, low-fidelity is faster and cheaper. Later, high-fidelity is more accurate and actionable.
What Are the Benefits?
Catch interaction problems early — navigating a prototype reveals gaps in user flows, dead ends, and confusing interaction patterns before a single line of code is written.
Usability testing vehicle — a clickable prototype gives test participants something realistic to interact with, producing feedback that's far more reliable than showing static screens.
Stakeholder alignment — interactive demos communicate design intent more clearly than still images, reducing misaligned expectations at handoff.
Reduced development cost — identifying and fixing interaction issues at the prototype stage is considerably cheaper than post-launch corrections.
What Are the Limitations?
No real performance data — a prototype simulates behavior but can't replicate actual load times, database queries, or edge cases that only surface in a live environment.
Time investment — high-fidelity prototypes take real effort to build and maintain, especially for products with many screens and states.
False sense of completion — a polished interactive prototype can look so close to finished that stakeholders underestimate the development work still ahead.
Where Does Prototyping Fit?
Prototyping sits after mockups and before development — the point where visual decisions get tested as a working system rather than evaluated as static images. In digital product design, it's one of six defined phases, sitting between design execution and user validation.
Once a prototype has been tested and refined, A/B testing offers a way to validate specific design decisions with live users at scale.