Idiom:  don't judge a book by its cover

Book cover with a microphone image and the sentence example, "Susan Boyle showed the judges on Britain's Got Talent why you shouldn't judge a book by its cover."


Idiom:  (you can’t/never/don't) judge a book by its cover

  • it's not good to decide about something based on its outward appearance only

Note:  In book publishing, an enormous amount of attention is put into the design of a book's cover because most people will not carefully read through the book before making a purchase. As a result, the cover of a book often does not closely match the book's contents.

Example sentences

— In Los Angeles, you can’t judge a book by its cover because some of the richest people shop in jeans and a T-shirt.

— Wow, chocolate-covered crickets are really delicious. It just shows that you can't judge a book by its cover.

— Try to keep an open mind about the new software updates.  It's never a good idea to judge a book by its cover.

— He seems really short to be a basketball player but after two decades coaching, I've learned to not judge a book by its cover.

— Marketers know very well that consumers will judge a book by its cover and this is why even the cheapest cosmetics come in attractive packaging.

— Fortunately, one of the valuable lessons my parents taught me was never to judge a book by its cover.

— If I'd judged a book by it's cover, I'd never have married the love of my life.

— When Susan Boyle sang on Britain's Got Talent, she proved that you can't judge a book by its cover.

— I know better than to judge a book by its cover because people always underestimate me and I'm always capable.

By the way, if you've never seen Susan Boyle's audition for Britain's Got Talent, you should watch it below!


  • all that glitters is not gold
  • looks can be deceiving

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