standpoint vs viewpoint

standpoint and viewpoint both are nouns.

Word	Noun	Adjective	Verb	Adverb
standpoint	Yes	No	No	No
viewpoint	Yes	No	No	No

As nouns, standpoint and viewpoint are synonyms defined as:

standpoint and viewpoint: a mental position from which things are viewed

Other synonyms of standpoint include point of view, stand.

standpoint (noun)	viewpoint (noun)
a mental position from which things are viewed	a mental position from which things are viewed
	a place from which something can be viewed