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

title	description	categories	keywords	params	aliases
strings.Contains	Reports whether the given string contains the given substring.			functions_and_methods aliases returnType signatures bool strings.Contains STRING SUBSTRING	/functions/strings.contains

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

The check is case sensitive:

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