greater / less — Power Automate (WDL) function reference

Numeric comparison.

Syntax

wdl

greater(value, compareTo) / less(value, compareTo)

wdl

greater(variables('total'), 1000)

→ true / false

wdl

greater(length(item()?['Description']), 500)

→ true / false

ISO-formatted date strings sort correctly with lexical comparison.

wdl

less(formatDateTime(utcNow(), 'yyyy-MM-dd'), formatDateTime(item()?['ExpiryDate'], 'yyyy-MM-dd'))

→ true / false

greater()/less() work on numbers and on ISO 8601 date strings directly, but comparing two strings that are neither valid numbers nor dates just does plain lexical comparison, which rarely gives the result you expect.
Mixing types, e.g. greater(5, '3'), throws rather than coercing — both arguments must resolve to the same comparable type.

From Logic & comparison