politeness vs niceness

politeness and niceness both are nouns.

Word	Noun	Adjective	Verb	Adverb
politeness	Yes	No	No	No
niceness	Yes	No	No	No

As nouns, politeness and niceness are synonyms defined as:

politeness and niceness: a courteous manner that respects accepted social usage

politeness (noun)	niceness (noun)
the act of showing regard for others	the quality of nice
a courteous manner that respects accepted social usage	the quality of being difficult to detect or analyze
	a courteous manner that respects accepted social usage