SearXNG allows you to modify the default categories, engines and search language via the search query.
! to set category and engine names.
: to set the language.
Abbrevations of the engines and languages are also accepted. Engine/category
modifiers are chainable and inclusive. E.g. with !map !ddg !wp paris
search in map category and duckduckgo and wikipedia for
See the preferences for the list of engines, categories and languages.
Search in wikipedia for
Search in category
Custom language in wikipedia: