The Brief:

IKR is an acronym for "I know, right." 

Bluesquiggle
DEEP DIVE

IKR is used as an expression of agreement. As the punctuation is nonexistent in the acronym-version of the phrase, context clues must be used to determine exactly what the intended tone is. IKR often connotes simultaneous shock and agreement.

Examples:

“Did you see what people are saying on Twitter about Prince William?!”

“IKR! It’s crazy! I’m disappointed but not surprised…”