A high-fidelity mockup shows what an interface will look like; a functional prototype shows what it will do. In this topic we examine that shift: what actually makes a prototype "functional," why polished static screens are not enough once real users sit down with your design, and how to decide when your team is ready to move from visual design tools into interactive or coded builds.
The practical pressure point is usability testing. If a participant taps a region that was never wired up, or needs data that your mockup only fakes with a screenshot, the test stops producing useful findings and starts producing apologies. That is why scoping matters: you do not build everything, you build the paths your test tasks require, at a fidelity that lets participants behave naturally and lets you observe where they struggle.
As you watch the videos below, keep three questions in mind. First, which parts of a design are being made real versus merely depicted? Second, what kinds of user behavior can each level of fidelity reveal, and what does it hide? Third, how would you trim a full product vision down to a testable slice that still implements the core features from your own project requirements?
Part of the Google UX Design Certificate series, this video walks through moving from lower-fidelity work into high-fidelity design, incorporating visual design elements, type, color and layout into new iterations of your screens. It is framed as a step in a larger design process rather than an endpoint, so it shows what a high-fidelity mockup actually delivers and where it sits in the workflow. Expect practical guidance on building polished iterations that are ready to be made interactive.
It gives you a clear, industry-standard picture of what a high-fidelity mockup is and is not, which is the necessary baseline for understanding the limitations discussed in this topic, and it comes from a widely used professional certificate program.
A beginner-oriented Figma tutorial focused specifically on the prototyping features of the tool: connecting frames, defining interactions and transitions, and turning static artboards into something a person can click through. It demonstrates the hands-on mechanics of adding behavior to screens you have already designed. The tutorial format means you can follow along with your own project files.
This is the most direct demonstration of the mockup-to-interactive transition, showing exactly which behaviors prototyping tools can simulate and, by implication, where you will need coded implementation instead.
A short, focused overview placing usability testing as the validation stage that follows prototyping in the design thinking process. In four minutes it introduces why testing happens after you have something users can interact with and what the step is meant to validate about earlier design decisions. It frames testing as a check on prior assumptions rather than a final rubber stamp.
It connects prototype readiness directly to the purpose of testing, which is the reasoning behind both transition-readiness criteria and prototype scoping, and its brevity makes it a useful conceptual anchor for the rest of the module.
Together these videos trace the arc of the module. The Google Certificate video establishes what a high-fidelity mockup contributes and where it stops, and the Figma prototyping tutorial supplies concrete technique for making those screens interactive, both supporting MO1 as you build a prototype that implements your project's core features. The usability testing overview supplies the rationale for MO2 by showing what the testing stage is meant to validate, which in turn shapes the task scripts and data you plan to collect. Taken as a set, they also inform MO3: knowing what a functional prototype must support before testing is exactly the standard against which you verify your build against the specified interface requirements.
These videos were chosen from YouTube on October 3, 2026. Each has captions; the player turns them on. Videos on YouTube can be changed or removed — if one no longer plays, tell your instructor. If a player does not appear, use its Watch on YouTube link.