What's the Difference Between UX Design and UI Design?

The terms UI (user interface) and UX (user experience) are very closely connected. Many people know there's a subtle but crucial difference between these two aspects of product design. But when asked what exactly that difference is, a lot of them can't put it into words right away. So we've put together a detailed summary of how the two concepts ultimately differ and what really matters in UI and UX. That way, the UX vs. UI question no longer has to be one of the great mysteries of professional product design.

The difference between UX and UI

In everyday use, the line between UX and UI often gets blurry. The terms are frequently – and wrongly – used as synonyms or thrown around in vague contexts. Yet there are key differences, and understanding them is essential for successful, user-focused product design. At its core, the difference between UX and UI comes down to how a website or app is perceived visually on the one hand, and how users feel while using it on the other. The two are certainly closely related, which is also why user interface design and user experience design are often mentioned in the same breath. When it comes to successfully designing a web application, however, the differences matter a great deal.

What is a user interface, or UI?

UI design, or user interface design, is about how users visually perceive a web application. It covers specific colors and shapes, but also where certain buttons sit in a navigation bar, how icons on the page resemble or differ from each other, and how consistent the look of the entire application is. At the same time, input fields in forms and the overall look of input pages should be both aesthetically pleasing and, above all, practical, so they leave the best possible impression on users. The user interface therefore defines the surface on which a user interacts with the application. It determines how easy navigation feels to users and how pleasant they find interacting with the machine. The central goals of user interface design are an intuitive, pleasant, and efficient user experience.

UI: The interface for optimal human-computer interaction

Ultimately, the user interface is about designing the interaction surfaces between humans and machines as well as possible. In the world of web applications, a further distinction is made between two aspects. On the one hand, there's optimizing the graphical user interface. This refers to the surface itself, which users navigate with a mouse, keyboard, or touch gestures. On the other hand, there's the web user interface. This is about designing interfaces that are displayed to users over the internet in a web browser.

What is user experience, or UX?

Now that we've pinned down exactly what user interface means in web design, let's move on to what's commonly called user experience. It should quickly become clear that there are key differences between these two aspects of web design. At the same time, it also becomes clear how closely the two concepts are linked – and that a good user interface designer can't get by without a solid understanding of user experience requirements. User experience is primarily about the feelings, attitudes, and opinions a person has toward a product or service as a whole. So the focus here is on usability and on how intuitive the application is to use. You've achieved a good user experience when users come away with a good feeling about the application overall. It quickly becomes obvious that user experience is a very subjective impression of a product. It's shaped by users' attitudes and experiences, but also by the specific purposes and expectations they bring to using the product. That's why, for successful user experience design, it's absolutely essential to precisely identify your target audience and user types and to understand their particular traits.

Thinking about user interface and user experience together

We've now taken a close look at the difference between UX and UI. From the previous sections, it should already be clear that you can't think about user interface without user experience. So let's take a closer look at how the two areas can be considered together in harmony without the differences getting blurred. It goes without saying that a beautiful product has no advantage whatsoever if you can't use it, or if using it is so cumbersome that users give up in frustration after just a few steps. It's equally clear that user-friendly navigation doesn't help much if the product isn't appealingly designed. Still, there are points where aesthetics and usability conflict. Sometimes the most beautiful product design simply isn't the easiest to use. And in some cases, you have to sacrifice aesthetics simply because the users' goals are so complex that there's little room for creative freedom. It's precisely in these edge cases that it's crucial to think about user interface and user experience together, and to carefully identify and resolve conflicts. Either way, the finished product has to meet users' high standards – and users generally don't like to compromise on either their overall experience or the product's design.

The biggest common ground: Always focus on the user

User interface design and user experience design share one core principle: the product must always be designed with users in mind. This insight hasn't always been the foundation of web development in particular. For a long time, technical developers called the shots, and they weren't especially interested in the needs of less tech-savvy users. But companies have since recognized how important it is to stop developing products that miss the mark with their customers. That has given UX and UI an enormous boost. This new mindset in web development has also helped spread user research (UR) across many fields. After all, the first requirement for a successful UX concept is knowing your users and being able to anticipate their intentions and expectations. One effect of this is that products are no longer programmed in independent, isolated steps. Here it's especially important to manage the entire user experience and guarantee consistently good usability across the whole product. That's the only way to keep users satisfied and get UI and UX to work in perfect harmony.

Conclusion: UX vs. UI is a matter of difference and harmony

First, we've successfully worked out the difference between UX and UI. Anyone should now be able to explain easily that user interface focuses on the design of the product, while user experience is specifically about users' actual experience with the product. These two concepts should never be lumped together. If you focus on only one of them, user-friendly web development is bound to fail. Ultimately, UX and UI have to work together, with aspects of both areas woven into each other. The entire product must always stay in view, and the focus must be on the individual characteristics of the users. Without user research as the perfect foundation, neither UI design nor UX design will work.