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

title	linktitle	description	date	publishdate	lastmod	categories	menu	keywords	signature	workson	hugoversion	relatedfuncs	deprecated	aliases
lower	lower	Converts all characters in the provided string to lowercase.	2017-02-01	2017-02-01	2017-02-01	functions	docs parent functions	strings casing	lower INPUT strings.ToLower INPUT				false

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

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