all important vs crucial

all important and crucial both are adjectives.

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

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

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

all important (adjective)	crucial (adjective)
of the greatest importance	of extreme importance; vital to the resolution of a crisis
	of the greatest importance
	having crucial relevance