Good search UX covers five moments: making the search bar findable, making typing productive with live suggestions, making results scannable and grouped, making filters visible and reversible, and making failure recoverable. Most sites invest in the third and neglect the first and fifth, which carry more of the outcome.
Persistent, open field in the header. Example-query placeholder. Keyboard shortcut on desktop. On mobile, do not let the on-screen keyboard cover the suggestion list — this single detail dominates mobile search satisfaction.
Show suggestions from the second character, mixing query completions, categories and a few concrete results. Highlight the matched substring. Keep the list short enough to scan and stable enough not to reshuffle under the finger.
Group by type when the site has more than one — products, pages, help, policies. Echo the query back. Show the result count. Preserve scroll position when a visitor returns from a result, which is the most common navigation in any search session.
Facets visible without a click on desktop, one tap away on mobile. Show counts. Only offer values present in the current set. Make every applied filter removable in one action and never allow a silent empty combination.
Never render a bare "no results". Show what was searched, offer a corrected spelling, relax the narrowest filter, suggest the nearest category, and provide a way to ask a person. Treat this screen as a design priority, not an error state.