like the devil vs like mad

like the devil and like mad both are adverbs.

Word	Noun	Adjective	Verb	Adverb
like the devil	No	No	No	Yes
like mad	No	No	No	Yes

As adverbs, like the devil and like mad are synonyms defined as:

like the devil and like mad: (informal) with great speed or effort or intensity; used for emphasis

Other synonyms of like the devil include like crazy, like hell, like sin, like thunder.

like the devil (adverb)	like mad (adverb)
(informal) with great speed or effort or intensity; used for emphasis	(informal) with great speed or effort or intensity; used for emphasis