insofar vs in so far

insofar and in so far both are adverbs.

Word	Noun	Adjective	Verb	Adverb
insofar	No	No	No	Yes
in so far	No	No	No	Yes

As adverbs, insofar and in so far are synonyms defined as:

Other synonyms of insofar include so far, to that degree, to that extent.

insofar (adverb)	in so far (adverb)
to the degree or extent that	to the degree or extent that