Slang dictionary · English internet slang · English internet slang
What does IYKYK mean?
Also written: if you know you know, iykyk, #iykyk
In short
IYKYK stands for "if you know, you know". People add it to a post or message to signal an inside joke, shared memory or niche reference that only certain readers will understand, without explaining it. Those who get it feel included; those who don't are meant to stay curious. The abbreviation has been used online since at least 2009 and became common in the mid-2010s.
Where IYKYK comes from
The phrase "if you know, you know" is older spoken English. Dictionary.com finds the abbreviation on social media from at least 2009, with use growing in the mid-2010s, and it is now a familiar hashtag. Cambridge describes it as a way to show there is shared knowledge with the reader that other people might not understand.
How to use it
- "Room 204 after the fire drill. IYKYK."
- "That one teacher who said 'I'll wait.' IYKYK."
- "Best tacos in the city are behind the gas station, iykyk."
- "90s kids and the dial-up sound. IYKYK."
Similar phrases
| Phrase | Meaning | Difference |
|---|---|---|
| IYKYK | if you know, you know | deliberately leaves others out |
| inside joke | a joke shared by a group | the thing itself, not a tag |
| no context | posting something without explanation | invites everyone to guess |
Tone
IYKYK is friendly and a bit mysterious. Used to tease an inside joke among friends it is fun; used by brands and influencers to hype a product, it can feel like gatekeeping or marketing. If people keep asking what you mean, just explain.
FAQ
What does IYKYK stand for?
If you know, you know.
How do you reply to IYKYK?
If you get it, react or add to the joke. If you don't, it is fine to ask; people often enjoy explaining.
Is IYKYK rude?
Not really, but it deliberately leaves some readers out, so overusing it can seem exclusive.