readily vs promptly

readily and promptly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
readily	No	No	No	Yes
promptly	No	No	No	Yes

As adverbs, readily and promptly are synonyms defined as:

Other synonyms of readily include pronto.

readily (adverb)	promptly (adverb)
without much difficulty	in a punctual manner
in a punctual manner	at once (usually modifies an undesirable occurrence)
	with little or no delay