hugo/docs/content/en/functions/strings/Contains.md

title	description	categories	keywords	menu	function	relatedFunctions	aliases
strings.Contains	Reports whether the string contains a substring.	functions		docs parent functions	aliases returnType signatures bool strings.Contains STRING SUBSTRING	strings.Contains strings.ContainsAny strings.ContainsNonSpace strings.HasPrefix strings.HasSuffix	/functions/strings.contains

{{ strings.Contains "Hugo" "go" }} → true

The check is case sensitive:

{{ strings.Contains "Hugo" "Go" }} → false