SuGoiSuす語彙すGrammar › N1 · 05 Contrast, comparison and extent
〜とは裏腹に: contrary to
N1 · 05 Contrast, comparison and extent
Says that something shows the opposite of what appears on the surface or what was said.
Noun or clause + とは裏腹に. The inside and outside do not match: words versus feelings. A literary and descriptive tone. Compare 〜に反して, which is a more neutral "against expectation".
Examples
明るい表情とは裏腹に、彼の心は不安でいっぱいだった。
Contrary to his cheerful face, his heart was full of worry.
期待とは裏腹に、結果は散々だった。
Contrary to my hopes, the result was terrible.