pettiness vs littleness

pettiness and littleness both are nouns.

Word	Noun	Adjective	Verb	Adverb
pettiness	Yes	No	No	No
littleness	Yes	No	No	No

As nouns, pettiness and littleness are synonyms defined as:

Other synonyms of pettiness include smallness.

pettiness (noun)	littleness (noun)
the quality of being unimportant and petty or frivolous	the property of having a relatively small size
lack of generosity in trifling matters	lack of generosity in trifling matters
narrowness of mind or ideas or views	the property of having relatively little strength or vigor