The phrase comes from a 2014 Vine by Peaches Monroee, filmed as a casual selfie video in which she praised her own eyebrows as being on fleek. The clip spread quickly across Vine, Twitter and Instagram, and on fleek soon became widely used slang for something looking perfect or flawless, especially in beauty and fashion posts. The sound later resurfaced on TikTok and in reaction videos, where creators kept using the original audio to mark a polished look. Its lasting appeal comes from that direct link to the moment the phrase entered popular culture.