unending vs perpetual

unending and perpetual both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unending	No	Yes	No	No
perpetual	No	Yes	No	No

As adjectives, unending and perpetual are synonyms defined as:

Other synonyms of unending include aeonian, ageless, eonian, eternal, everlasting, unceasing.

unending (adjective)	perpetual (adjective)
continuing forever or indefinitely	uninterrupted in time and indefinitely long continuing
	continuing forever or indefinitely