# you can't judge a book by its cover

idiom · CEFR B1

Source: https://englishreference.com/idiom/you-cant-judge-a-book-by-its-cover
Updated: 2026-08-10

## Meaning

It is not possible to make reliable judgments about things or people by considering external appearances alone.

## Examples

- 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.

## 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). (disputed)

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.