hugo/docs/content/en/functions/lower.md

title	description	categories	menu	keywords	signature	relatedfuncs
lower	Converts all characters in the provided string to lowercase.	functions	docs parent functions	strings casing	lower INPUT strings.ToLower INPUT

Note that lower can be applied in your templates in more than one way:

{{ lower "BatMan" }} → "batman"
{{ "BatMan" | lower }} → "batman"