UI

The UI is the surface. How the button looks, how big the text is, what colour the links are and what happens when you tap. A good UI is consistent. Things that are alike look alike and behave alike on every page.

UI and UX are not the same

UX is what it is like to use the site, from the search until the booking is sent. The UI is the concrete parts you use along the way. A pretty UI can hide poor UX: a beautiful button does little good if it sits on the wrong page. And a site with a plain, almost boring UI can give good UX, because everything is where the customer expects it.

Small flaws, big consequences

Much of what makes a site hard to use comes down to UI mistakes that are easy to fix. Light grey text on a white background is tiring to read. Buttons too small for a thumb cause mis-taps. Links that do not look like links do not get clicked. Contrast is also a requirement in WCAG, the standard behind web accessibility: normal text needs a contrast ratio of at least 4.5:1 against its background, according to W3C.

The thumb test

Take your phone outside in daylight and open your website. Can you read all the text without squinting? Do you hit every button on the first try? Note what was difficult, and send the list to whoever builds or runs the site.