no really vs you don't say

no really

intj

  • no kidding!; is that so? (sometimes used sarcastically in response to the obvious) 

adv

  • really; seriously; used to attempt to introduce a serious point in a less serious conversation 

you don't say

intj

  • Really?; no kidding!; is that so? (sometimes used sarcastically in response to the obvious) 

How often have the words no really and you don't say occurred in a corpus of books? (source: Google Ngram Viewer )