UI vs. UX: 6 Key Differences & Examples

A user interface (UI) is the visual and interactive layer of a product while the user experience (UX) is the broader experience of using it.

For online store owners comparing UI and UX, they often need to decide which skills to hire for and where to focus a redesign. Identifying the distinction between UI versus UX helps you describe whether shoppers struggle with the path through your store, the controls they use, or both.

This guide compares UI and UX across six areas: focus, scope, goals, process, outputs, and measurement.

What is UX?

User experience (UX) is the full experience a person has with a company, product, or service before, during, and after they use it. While it includes digital interactions, it doesn’t stop at the screen.

The Interaction Design Foundation describes UX design as shaping the entire process of acquiring and integrating a product, including branding, usability, function, and related experiences such as marketing, packaging, and after-sales support. 

Nielsen Norman Group takes a similarly broad view, defining UX as encompassing “all aspects of the end-user’s interaction” with a company, its services, and its products.

For an ecommerce business, that user experience could begin with how easily a shopper understands what you sell, continue through search, navigation, product pages, checkout, and delivery, and extend to packaging, returns, and customer support. 

Some of those touchpoints have a user interface. Others don’t. But they can all shape the UX regardless.

Peter Morville’s classic user experience honeycomb breaks UX into seven qualities: useful, usable, desirable, findable, accessible, credible, and valuable.

You can see several of these UX qualities at work on ThirdLove’s online storefront. Their Find My Fit tool helps shoppers narrow down sizing and styles, while accessibility controls give visitors additional ways to adapt the interface.

What does a UX designer do?

A UX designer figures out what users need, maps how they’ll move through a product or service, and tests whether the resulting experience works as intended. 

The exact scope varies by company, but common responsibilities include:

• Researching users. Conduct interviews, surveys, observation, or other research to understand customer goals, behaviors, and pain points.
• Mapping journeys and flows. Plot the steps users take through a product or service, from their first interaction through key tasks and follow-up experiences.
• Structuring information. Organize navigation, categories, content, and page relationships so people can find what they need.
• Creating wireframes and prototypes. Turn ideas into early layouts and interactive flows before investing in a finished interface.
• Running usability tests. Watch people complete tasks, identify where they hesitate or get stuck, and test potential fixes.
• Analyzing and iterating. Combine research findings, usability feedback, and behavioral data to refine the experience over time.
• Collaborating across teams. Work with UI designers, developers, product managers, marketers, and other stakeholders to carry research findings into the finished product.

Nielsen Norman Group’s UX careers research shows how broad the field can be, spanning research, interaction design, information architecture, prototyping, usability testing, and other specializations. The Interaction Design Foundation similarly describes UX design processes as an iterative process of researching users, designing solutions, testing them, and refining the result.

On Shopify, UX teams can pair that qualitative work with storefront data. Shopify Analytics includes behavior reports for conversion funnels, searches with no results, searches with no clicks, landing pages, and sessions by device. If research shows shoppers are struggling with product discovery, for example, teams can then use Shopify Search & Discovery to refine filters, search synonyms, search results, and product recommendations.

What is UI?

User interface (UI) is the collection of controls, visuals, and other inputs through which someone interacts with a digital product. Most ecommerce interfaces are graphical, but the UI isn’t limited to screens. 

The Interaction Design Foundation distinguishes between graphical, voice-controlled, and gesture-based interfaces. A shopper might click a button, give a voice command, or use a gesture to control an experience.

In an online store, UI includes navigation menus, search bars, filters, product cards, variant selectors, quantity controls, add-to-cart buttons, checkout fields, and the messages that tell shoppers what happened after an action. The job is to make the controls easy to perceive and operate.

That’s what accessibility is all about. According to WCAG 2.2’s Target Size (Minimum) criterion, pointer targets should generally be at least 24 by 24 CSS pixels, or have sufficient spacing when they’re smaller, subject to specified exceptions. 

W3C explains that appropriately sized or spaced controls reduce accidental selections and make touch interfaces easier to use, particularly for people with limited fine motor control.

UI can also carry the character of the store itself. For example, when Spanish retailer Natura Selection moved to Shopify, they created different product-page templates for fashion and other product categories, combining technical product information with photography, editorial content, and social media collaborations. 

The company wanted their ecommerce storefront to reflect the distinctive experience of their physical stores rather than flatten every product into the same template. They reported a 13% increase in conversion and a 3% increase in add-to-cart rate after the broader replatforming.

“Shopify allowed us to offer editorial and multimedia content in each product template to replicate Natura physical stores’ characteristic immersive experience,” says Chiara Castellani, head of digital and ecommerce at Natura Selection.

What does a UI designer do?

A UI designer turns a product’s structure and functionality into an interface people can understand and operate. 

This could include:

• Designing interface elements. Create buttons, menus, forms, search fields, product cards, icons, and other controls.
• Establishing visual hierarchy. Use typography, spacing, color, imagery, and layout to make important information and actions easy to spot.
• Designing interaction states. Show what happens when someone hovers, taps, selects an option, encounters an error, or completes an action.
• Building design systems. Define reusable components and patterns so the interface stays consistent across pages and devices.
• Designing responsively. Adapt layouts and controls for different screen sizes rather than simply shrinking the desktop experience.
• Accounting for accessibility. Design controls, text, focus states, contrast, and other interface elements so more people can perceive and operate them.
• Prototyping and collaborating. Create mockups or interactive prototypes, then work with UX designers and developers to refine and implement them.

On Shopify, you’ll see some of that work in the theme editor. A storefront is assembled from configurable sections and blocks—such as text, images, buttons, and other content—and designers can rearrange them, adjust theme-wide settings such as typography and color, and switch to a mobile preview to see how the interface behaves on a smaller screen. 

UI vs. UX design: 6 key differences

UX and UI overlap heavily, but they operate at different levels. Jakob Nielsen says in a UX Tigers YouTube video that UI is what people interact with; UX is the experience they have while doing it.

In Jakob’s explanation of UI vs. UX, he says that UI can include screens, buttons, menus, copy, layouts, gestures, or voice controls, while UX is “the totality of everything they encounter.” 

His broader point is that a user interface shapes the experience, but it isn’t the whole experience. 

How UX and UI work together

UX and UI are interdependent: UX establishes what an experience needs to help people accomplish, while UI gives people the controls and cues they use to accomplish it. 

As Jakob Nielsen says, “User experience lives through the user interface.”

Neither can compensate indefinitely for the other. A beautiful storefront can still produce poor UX if shoppers struggle to find products, understand shipping costs, or recover from an error. Nielsen Norman Group calls this the “aesthetic-usability effect”: attractive interfaces can make people perceive a product as easier to use, but severe usability problems eventually override that goodwill.

The reverse is possible too. A store might have a sensible product hierarchy, a short checkout flow, and accurate search results, but cramped buttons or weak visual hierarchy can make for a poor UX.

Take Ronaldo Jewelry. Their old storefront had cumbersome navigation, long product pages, and weak mobile performance. But the UX problem was broader still: Shoppers had trouble browsing products and moving smoothly toward checkout. 

Their UI response included filterable collections, dynamic variant displays, condensed mobile product pages, a sticky search bar, and a sticky Add to Cart button. After the move to Shopify, Ronaldo Jewelry reported a 100% increase in conversion rate and a 34% increase in checkout completion.

The role of UI and UX in ecommerce

In ecommerce, UX and UI show up in how quickly customers can find a product, whether a product page answers their questions, how well the store works on mobile, and how many steps it takes to check out.

The Shopify store Groupe Marcelle, for example, combined a mobile-first UX/UI overhaul with faster performance, improved navigation, and reusable storefront components when they migrated their brands to Shopify. Marcelle and Lise Watier subsequently reported a 6% improvement in conversion rate, alongside 32% sales growth.

That’s why, for an ecommerce store, UX and UI have a shared job:

• Make products easier to find. Use clear category names, search, filters, sorting, autocomplete, and relevant recommendations where they shorten the path to a product. Shopify’s free Search & Discovery app lets merchants customize filters, create synonym groups, boost products for particular searches, add related and complementary products, and review search analytics.
• Help shoppers make decisions. Product pages should answer the questions standing between interest and purchase. Depending on the product, that might mean prominent variant selectors, size or compatibility information, shipping details, reviews, comparison tools, or persistent add-to-cart controls.
• Remove friction at checkout. Shopify stores use one-page checkout by default, while accelerated checkout methods can prefill saved payment and shipping information or let eligible shoppers move directly from a product page to checkout. Shop Pay can save a customer’s email, payment method, and shipping and billing information for faster subsequent checkouts. 
• Make the storefront usable by more people. Shopify’s theme accessibility guidance recommends sequential heading structures, readable body text, links that aren’t distinguished by color alone, descriptive image alt text, controllable video and slideshows, and visible keyboard-focus states for interactive elements. 
• Design for the device shoppers are using. The job doesn’t end with responsive UI. Besides load times, tap targets, navigation, and content order, a mobile user’s experience depends on how much scrolling or typing they need to do.

When sustainable fashion brand ARMEDANGELS replatformed to Shopify, they treated mobile experience and accessibility as “non-negotiable.” Their relaunch included clearer ecommerce navigation, new product and collection structures, improved accessibility, and a new checkout; mobile conversion increased 18% in the first three months. 

Accessibility requirements vary by jurisdiction and by the circumstances of your business. Consult a qualified legal professional about the requirements that apply to your store.

Do you need a UI designer, a UX designer, or both?

Not every ecommerce store needs separate UI and UX specialists. The right level of design support depends on the problem you need to solve:

• Hire a UX designer when the digital customer journey is the problem. Your customers have trouble finding products, your navigation has become cluttered, important information appears too late, or you’re redesigning a complicated path like product discovery or checkout.
• Hire a UI designer when the structure works, but the interface needs attention. The store may be functionally sound but visually inconsistent, difficult to scan, awkward on mobile, or missing a coherent component system. 
• Hire both types of designers for a substantial redesign. A new storefront, replatforming project, major navigation overhaul, or complex custom shopping experience usually involves decisions at both levels. The UX work establishes what customers need and how the journey should work; UI design turns that into the screens and interactions customers use.

There’s also a scenario in which you don’t need either, at least for the time being. Shopify store owners can start with a prebuilt theme rather than designing an entire storefront interface themselves. The Shopify Theme Store includes free Shopify-developed themes and paid third-party themes. You can search by using filters for features such as product filtering, quick buy, related products, and sticky navigation. 

Read the full guide on how to design your own Shopify storefront in six steps. 

You still need to choose navigation, organize products, write clear content, test the store on different devices, and watch where customers struggle.

If you do need specialist help, the Shopify Partner Directory lets you find and contact Shopify Partners offering services including store setup, development and troubleshooting, and visual content and branding.