# What is UI – User Interface?

What is UI – User Interface? The visual design of the site — colors, typography, icons, layout, spacing.

## How it works in practice

UI is the 'visual language' that speaks to a visitor before they read a word. Colors: blue signals trust, orange signals urgency. Whitespace signals luxury. A cluttered design signals low price. A luxury store with a 'cluttered' design sends the wrong message.

## Related metrics

- UX — UI is a component of UX
- Brand Identity — UI expresses brand identity
- CRO — UI affects CR
- Typography — a core part of UI

## Common misconception

'UI is just decoration — it doesn't affect sales.' Stanford research found 75% of users judge a company's credibility by its site design. Poor UI means low trust means low CR. Sometimes improving UI (images, layout, whitespace) increases CR more than a price change does.

## How to fix it

UI falling short? (1) Use a color contrast checker — is text readable? (2) font size: minimum 16px for body text, (3) whitespace: is the page too crowded? (4) consistency: are buttons, colors, and fonts uniform across the site? (5) image quality: high-resolution photos with professional lighting.

## Real-world example

A jewelry store had an outdated UI, gray-background photos, and a hard-to-read font. A redesign with white-background photos, a clean font, and more whitespace raised CR from 0.9% to 2.1% with no change in price or traffic — UI alone.

## Where to start

Run a UI audit: look at the store on someone else's screen. What's the first impression? Does it look professional? Are the images high quality? For new stores: invest in professional photography before any advertising — high ROI.

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Category: Customer Experience · From the [Jimmy OS KPI Glossary](https://jimmy-os.com/glossary/kpi.md) · Source page: https://jimmy-os.com/glossary/kpi/ui-user-interface