as yet vs thus far

as yet and thus far both are adverbs.

Word	Noun	Adjective	Verb	Adverb
as yet	No	No	No	Yes
thus far	No	No	No	Yes

As adverbs, as yet and thus far are synonyms defined as:

as yet and thus far: used in negative statement to describe a situation that has existed up to this point or up to the present time

Other synonyms of as yet include heretofore, hitherto, so far, til now, until now, up to now, yet.

as yet (adverb)	thus far (adverb)
used in negative statement to describe a situation that has existed up to this point or up to the present time	used in negative statement to describe a situation that has existed up to this point or up to the present time