The short version: UX is what the product does and how it is organised. UI is what you see and touch. If UX decides that a checkout should be three steps and what belongs in each one, UI decides what those steps look like, how the buttons behave, and what happens when the card is declined.
The longer version matters if you are hiring, because job titles in this field are used so loosely that two people with the same title can have almost nothing in common.
What a UX designer does
UX design is structural. The work is mostly about deciding what should exist and in what order, and it happens before anything looks like anything.
- Talking to users and working out what problem is actually being solved
- Mapping flows: the paths a person takes to get something done
- Information architecture: what is grouped with what, what is called what
- Wireframes: layout and hierarchy with the styling deliberately absent
- Prototyping and testing, then changing their mind based on what happened
The deliverables are often ugly on purpose. A wireframe in grey boxes keeps the conversation on whether the structure works instead of whether the blue is right.
What a UI designer does
UI design is the surface, which is a much bigger job than “making it pretty.”
- Visual system: type scale, colour, spacing, the rules that make a hundred screens feel like one product
- Components and states: default, hover, focus, active, disabled, loading, error, empty
- Responsive behaviour from small phones to large monitors
- Accessibility: contrast, target sizes, focus order, and whether it works without a mouse
- Motion and feedback: what confirms to someone that the thing they did worked
Most of a UI designer’s time goes into the states nobody demos. The happy path is the easy part.
Side by side
| UX designer | UI designer | |
|---|---|---|
| Main question | Should this exist, and in what order? | How does this look and behave? |
| Typical output | Flows, wireframes, IA, research findings | Visual system, components, final screens |
| Works from | User problems and business goals | Structure and brand |
| Fails by | Building the wrong thing well | Building the right thing badly |
| Measured by | Can people complete the task? | Is it clear, consistent, and does it hold up? |
Why the titles blur
Outside large product organisations, almost nobody does only one of these. “UI/UX designer” exists as a title because most companies need both, cannot justify two hires, and the two disciplines are genuinely hard to separate in practice. You cannot design a flow without some sense of what fits on a screen, and you cannot design a screen well without understanding what the person is trying to do.
There are also adjacent titles that overlap heavily. A product designer usually covers both plus a share of the product thinking. A UX researcher does the discovery half only. An interaction designer sits closest to behaviour and motion. A UX writer owns the words, which is far more consequential than it sounds.
Which one do you need?
You probably need UX first if: people are dropping out partway through, support keeps answering the same question, nobody agrees what the product is for, or you are about to build something new.
You probably need UI first if: the product works but looks dated or untrustworthy, the interface is inconsistent across screens, or engineering is inventing visual decisions because nothing is defined.
You need both if you are building a new product surface, which is the usual case, and why most people hire one person who does both.
A caution: the visual problem is easier to see, so it gets prioritised. Restyling a confusing product gives you a confusing product with better typography.
How to check what someone actually does
Ignore the title and look at the artefacts. Ask to see a flow or a wireframe from a real project, and separately ask to see a component library or a set of states. Most designers are noticeably stronger on one side, which is fine as long as you know which side.
Then ask them to walk you through a decision they changed their mind about. Structural thinkers will describe a flow they reorganised. Surface thinkers will describe a pattern they rebuilt. Someone who genuinely does both will have examples of each.
There is a longer list in questions to ask when hiring a UX designer.
Frequently asked questions
Can one person do both well?
Yes, and most working designers outside big tech do. What varies is the depth. A generalist covering both will rarely match a dedicated researcher on discovery or a dedicated visual designer on craft, and for most projects that trade is worth making.
Which one pays more?
They are close, with product designers who cover both typically at the top. Rates depend far more on seniority, region and whether someone can also build than on which of the two labels they use. See what a UI/UX designer costs.
Is UX just research?
No. Research informs UX, but the design work is deciding structure and flow. Plenty of strong UX designers do relatively little formal research and lean on domain knowledge, analytics and testing instead.
Do I need a UX designer for a small marketing site?
Rarely as a separate hire. A five-page site needs clear structure and good visual craft, which one competent designer handles. Separate UX effort starts paying off when there are real flows: signup, checkout, configuration, anything with steps and states.
Where does front-end development fit?
Outside both, though the boundary is soft. Some designers build what they design, which removes the handoff gap entirely. That is how I work, and you can see the results in my case studies.
Planning a website or product design project?