kind of vs kinda

kind of and kinda both are adverbs.

Word	Noun	Adjective	Verb	Adverb
kind of	No	No	No	Yes
kinda	No	No	No	Yes

As adverbs, kind of and kinda are synonyms defined as:

Other synonyms of kind of include rather, sort of.

kind of (adverb)	kinda (adverb)
to some (great or small) extent	to some (great or small) extent