Use a proper input size
The search input size should be wide enough to fit a typical search query. Short search inputs force users to use fewer and shorter keywords, which, in turn, leads to bad search queries and poor search results that negatively affect the user experience.
The Nielsen Norman Group recommends using 27-character-long search inputs as it makes search requests easier to read and interpret for users.[1]
References
- Top 10 Guidelines for Homepage Usability | Nielsen Norman Group