itty-bitty vs itsy-bitsy

itty-bitty and itsy-bitsy both are adjectives.

Word	Noun	Adjective	Verb	Adverb
itty-bitty	No	Yes	No	No
itsy-bitsy	No	Yes	No	No

As adjectives, itty-bitty and itsy-bitsy are synonyms defined as:

Other synonyms of itty-bitty include bittie, bitty, teensy-weensy, teensy, teentsy, teeny-weeny, teeny, wee, weensy, weeny.

itty-bitty (adjective)	itsy-bitsy (adjective)
(used informally) little or tiny	(used informally) little or tiny