you can't judge a book by its cover
It is not possible to make reliable judgments about things or people by considering external appearances alone.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“Don't judge a book by its cover when meeting new people.”
“You can't judge a book by its cover when you shop at thrift stores.”
“That fruit looks strange, but remember you can't judge a book by its cover.”
“The restaurant looks plain from the street, but you can't judge a book by its cover because the food is amazing.”
“The old car looks like a total wreck, but you can't judge a book by its cover because the engine runs perfectly.”
“She seems very quiet and shy in meetings, but you can't judge a book by its cover since she is a bold leader.”
“The hotel lobby is dark and messy, but you can't judge a book by its cover because the rooms are actually clean and modern.”
“Although the candidate appeared nervous and unpolished during the interview, the manager remembered that you can't judge a book by its cover and hired him for his brilliant technical skills.”
first recorded 19th c. disputed origin
The phrase in its modern form dates from the mid-20th century; the underlying idea appears earlier, e.g. in George Eliot's The Mill on the Floss (1860).
- 01
bad books
Disfavor.
- 02
balance the books
To add up all the debits and credits.
- 03
Barnaby Rudge
[Cockney slang]judge
- 04
beggars can't be choosers
Something is better than nothing: those who can't provide for themselves should accept whatever help is available.
- 05
blot one's copy book
To damage one's own reputation through bad behavior.
- 06
blow someone's cover
To reveal that someone's behavior, situation, or identity has been fabricated or deliberately misrepresented for an ulterior motive.
- 07
book burning
Any mass destruction, removal, or recalling of books, motion pictures, broadcasts, or electronic works as a form of censorship, especially motivated by religious or political objections to the material.
- 08
book dumping
The practice of donating old used books that burden rather than assist communities.
Last updated August 10, 2026