at last vs in the end

at last and in the end both are adverbs.

Word	Noun	Adjective	Verb	Adverb
at last	No	No	No	Yes
in the end	No	No	No	Yes

As adverbs, at last and in the end are synonyms defined as:

Other synonyms of at last include at long last, finally, ultimately.

at last (adverb)	in the end (adverb)
as the end result of a succession or process	as the end result of a succession or process
	eventually or after a lengthy period of time