For those who don’t know, there is a classic confusion among the term UX and UI. User experience (or UX) is streamlining how people move through intent. Business goals are often added alongside this flow. User interface (or UI), is commonly where a user moves through that flow. User interface is commonly visual in nature, but it may also be oral, aural, or even smell-based.
Because UX is a much wider field of design than UI, UX professionals regularly are frustrated by the confusion, leading some teams to rename their UX offerings as XD (or Experience Design). It also has lead to the side effect of looking down on UI design as of lesser importance than UX.
But UI is exclusively a UX exercise.
While looking “nice” is subjective to the brand and its personality, legibility remains a constant – a UX principle. Using a circle for selection regions on a form input implies you may only select one of the options shown, another principle known as an affordance, mapping to a user’s mental model of shape to a specific action – another UX principle.
And when both a selection action and a submission action are required, a switch (or toggle) removes one more barrier in the way of intent, compared to a checkbox and a submit button – again another UX principle. In fact, at my current company, we’ve spent time mapping out exactly which form inputs to use when to reduce mental load for users.
Accessibility, localization, motion, sound, affordances, and UX laws are all aspects of great UI design. Test your UI, see what is fastest, reduces errors, and is dead simple to use. In the end, what reduces the pathway to intent being confidently carried out?
So yes, UI design is UX design.