To say "don't judge a book by its cover"

[Gustaf Drevin]

Hi! You have helped me a lot here before, so I will post another question. It's a question on idioms, and I would love to know how to say "Don't judge a book by its cover" in French. Suggestions??

Merci d'avance!

[George Hunt]

There are quite a few examples on this page

 

http://www.linguee.fr/anglais-francais/traduction/judge+a+book+by+i...

 

I have no idea how common the phrases are.

[Erwan]

Ne pas se fier aux apparences orL'habit ne fait pas le moine are really common.