instead vs alternatively

instead and alternatively both are adverbs.

Word	Noun	Adjective	Verb	Adverb
instead	No	No	No	Yes
alternatively	No	No	No	Yes

As adverbs, instead and alternatively are synonyms defined as:

Other synonyms of instead include or else.

instead (adverb)	alternatively (adverb)
in place of, or as an alternative to	in place of, or as an alternative to
on the contrary