you can't tell a book by its cover

Proverb

alt-of alternative

Alternative form of you can't judge a book by its cover

Japanese Meaning

外見だけでは本質や価値を判断できない / 見た目だけで、そのものや人の真の性質を推し量ることはできない

She reminded him that you can't tell a book by its cover when he dismissed the shy candidate.

彼女は、内気な候補者を否定したときに、外見だけで人を判断してはいけないと彼に言い聞かせた。

Sense（1）

Alternative form of you can't judge a book by its cover