Site search is a feature used by a smaller share of visitors, but with markedly higher intent, because they know what they want. Which makes it worse when they find nothing. Usable search has several characteristics. The field is visible and in the same place across the site, not hidden behind an icon on mobile. It handles typos, inflection and synonyms, since people don't type exact terms. It offers autocomplete with the most common queries. Results can be filtered and are sorted by relevance, not by date. And on a zero-result search it offers alternatives instead of an empty page. Record users' search queries – they are the cheapest list of what is missing from the site or cannot be found. Turn on internal search tracking in your analytics; it tends to be switched off, and without it you know nothing about these queries.
See also: Internal site search as a topic source, Error states and empty pages, Navigation and menu.
