all-important vs all important

all-important and all important both are adjectives.

Word	Noun	Adjective	Verb	Adverb
all-important	No	Yes	No	No
all important	No	Yes	No	No

As adjectives, all-important and all important are synonyms defined as:

Other synonyms of all-important include crucial, essential, of the essence.

all-important (adjective)	all important (adjective)
of the greatest importance	of the greatest importance