instead vs or else

instead and or else both are adverbs.

Word	Noun	Adjective	Verb	Adverb
instead	No	No	No	Yes
or else	No	No	No	Yes

As adverbs, instead and or else are synonyms defined as:

Other synonyms of instead include alternatively.

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