visualiser vs visualizer

visualiser and visualizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
visualiser	Yes	No	No	No
visualizer	Yes	No	No	No

As nouns, visualiser and visualizer are synonyms defined as:

visualiser and visualizer: one whose prevailing mental imagery is visual

visualiser (noun)	visualizer (noun)
one whose prevailing mental imagery is visual	one whose prevailing mental imagery is visual