UX glossary
Prototype
A prototype is an early, testable model of a product. It lets you check ideas with real people before time and money go into development.
Imagine a team planning an app for booking hair appointments. Before anyone writes a line of code, the team wants to know: Can people find a free slot? Do they understand how to cancel it again? That is exactly what a prototype is for: a trial version that feels like the future product but only does as much as those questions require.
Explained simply
In digital product design, a prototype plays the same role as a cardboard model or a show apartment in construction: you can try something out before the real building exists. It shows how a product could look and work, and turns an idea into something people can actually touch instead of just talk about.
The Nielsen Norman Group describes a prototype, in essence, as a proposed solution to a specific design problem, which makes it a hypothesis: an assumption that still needs to be tested. The most direct way to test it is to watch people use it.
From paper sketch to clickable mockup
Prototypes differ mainly in their level of detail, known as fidelity. A low-fidelity prototype can be a hand-drawn sketch on paper or a simple wireframe. A high-fidelity prototype, on the other hand, looks almost like the finished product, with real colors, copy and working clicks, usually built in design tools like Figma.
Fidelity doesn’t have to be equally high everywhere. A prototype can look rough but contain complete content. Or it can look polished while covering only a few click paths. Both have their advantages: rough drafts are quick to make and invite honest criticism because they clearly look unfinished. Detailed mockups show more realistically how people will behave later, but they take more time.
An example
Back to the hair salon app. In the first week, the team sketches three versions of the booking screen on paper and asks five people from other departments to “book” an appointment with them. It quickly becomes clear that a calendar view works better than a long list. Only then does the team build a clickable mockup and test it with regular customers of a salon. That test reveals that nobody can find the cancel link. Fixing it in the prototype takes a few minutes. In the finished product, it would take days.
Why prototypes pay off
Changing a prototype is far cheaper than changing finished code. Prototypes also make sure everyone on the team is talking about the same thing: a clickable mockup ends many discussions that would otherwise go in circles. And they are the basis for usability testing, where you watch where people get stuck.
It’s worth separating a prototype from a minimum viable product (MVP). A prototype is for learning and is often thrown away. An MVP is a first real version that people actually use. You can read more in Minimum Viable Product (MVP): What UX Designers Should Know.
In practice
- Question first, prototype second. Write down what you want to find out. The question decides how detailed the prototype needs to be.
- As rough as possible, as detailed as necessary. Paper is often enough for structure and flows. Questions about readability or animations need a more detailed mockup.
- Click through it yourself before testing. A dead link or a missing screen throws participants off and skews your results.
Related terms
Wireframe, Usability Testing, Design System