What does 'BFF' stand for?

“BFF” stands for “best friends forever,” a phrase for a very close friendship that is imagined as lasting permanently. It is commonly used as a noun—“She is my BFF”—or as an affectionate label between friends.

The initialism became especially widespread through instant messaging, mobile texting, social networks, and youth culture, where short expressions were convenient and emotionally expressive. The underlying idea of a best friend is much older, but BFF gave that relationship a compact, memorable label. The phrase was also popularized in mainstream culture, including the television series Friends, where Phoebe explains the initialism.

BFF does not strictly mean that two people will remain friends forever, nor does it require that they have only one best friend. It is often playful, hyperbolic, or affectionate rather than a formal description of a relationship. “Best friends for life” is a related phrase, but it is not what the letters in BFF conventionally expand to.

The term is not limited to children or teenagers. Adults may use it sincerely, jokingly, or in captions and social-media posts. “BFFs” is the usual plural form.