Idiom
Let the cat out of the bag
By EasySay. Published . Updated .
Let the cat out of the bag means to reveal a secret by mistake.
The picture is a bag that should have stayed shut, springing open. People say “I let the cat out of the bag about the party” when the surprise is spoiled. Own it fast with a sorry: secrets, like cats, do not go back in.
Written for EasySay, in our own words.
In short
- AvoidIt is a slip, not a leak.
- Or saySpill the beans
- AUThe dictionaries we checked give it no style label and no Australian label, so it is everyday general English.
Let the cat out of the bag: what it is, and what it is not
- IS
- Revealing a secret by mistake; spoiling a surprise.
- IS NOT
- About a cat springing out of a bag: it means revealing a secret by mistake.
Meaning: To reveal a secret by mistake; to spoil a surprise.
How do people say it?
- In conversation:
Sorry, I let the cat out of the bag about your visit.
- At work:
The memo let the cat out of the bag before the launch.
Check yourself
What should I know?
The words say
To open a bag and let the hidden cat spring out.
It really means
To tell what should have stayed secret.
What do dictionaries say?
- In Australia
- The dictionaries we checked give it no style label and no Australian label, so it is everyday general English.
- In the UK
- The dictionaries we checked give it no British label, so it is general English, not only from the UK.
- In the US
- The dictionaries we checked give it no American label, so it is general English, not only from the US.
What mistakes should I avoid?
- It is a slip, not a leak. Do not use it for secrets told on purpose to harm.
- Say “the cat out of the bag”, not “a cat”. The words stay the same.
- Own it fast. A quick sorry beats a long excuse, and the beans agree.
The picture is a market bag tied shut against curious eyes. Then the knot slips, the cloth gapes, and the cat springs free across the stalls. No catching it now; cats do not queue to be re-bagged.
Every slipped secret runs the same half-second: the word out, the eyes wide, the room changed. The idiom lives in that half-second after, when the only move left is the honest one. Name the slip, say sorry, and help mend the surprise.
The mending matters more than the mistake. “Sorry, I let the cat out of the bag about your visit” works because it owns the slip in the open, cat and all. Excuses — tiredness, trickery, “anyway” — only re-tie an empty bag.
Its twin, “spill the beans”, teaches the same repair, and the two share examples freely: beans for plans, cats for surprises, sorry for both. Learn them as one shelf of slips-and-sorries and neither will fail you.
“Curiosity killed the cat” completes the small cat family, and the three repay learning together. Curiosity warns before the prying; the bag owns after the slip; the beans stand beside as the twin.
Warn, slip, own: three beats of one story about things better kept. Practise all three aloud this week — the warning to a friend, the sorry for a slip — and the cats will guard your secrets well.
What else can I say?
- Spill the beans The twin; same slip, same sorry.
- Give the game away British; to show the secret plan.
- Blurt out Plain; to say it before thinking.
More idioms
- Curiosity killed the cat A friendly warning that being too curious, or looking into private things, can cause trouble.
- Spill the beans To tell a secret, usually by mistake or too early.
More examples
- In a text:
Oops. Let the cat out of the bag. Sorry.
Questions people ask
Is it the same as “spill the beans”?
Nearly. They are twins: beans for plans, cats for surprises, and a fast sorry for both.
Was there a real cat in a bag?
Old tales say market sellers hid cats in bags, but the tales are shaky. The page shows no origin; the meaning is the slipped secret.
How do I fix a slipped secret?
Own it fast: name the slip, say sorry, and offer to mend. Excuses only re-tie an empty bag.
Sources and dates
- EasySay's own writing for the idioms, EasySay. Licence: original writing for EasySay. Checked .
Cite this page
EasySay. "Let the cat out of the bag". https://easysay.org/idioms/let-the-cat-out-of-the-bag. Last updated 23 October 2026.
https://easysay.org/idioms/let-the-cat-out-of-the-bag