unsure vs uncertain

unsure and uncertain both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unsure	No	Yes	No	No
uncertain	No	Yes	No	No

As adjectives, unsure and uncertain are synonyms defined as:

unsure and uncertain: lacking or indicating lack of confidence or assurance

Other synonyms of unsure include incertain.

unsure (adjective)	uncertain (adjective)
lacking or indicating lack of confidence or assurance	not established beyond doubt; still undecided or unknown
lacking self-confidence	lacking or indicating lack of confidence or assurance
	not certain to occur; not inevitable
	not established or confirmed
	ambiguous (especially in the negative)
	not consistent or dependable
	subject to change