boo is a Twitch emote typically used to playfully mock, taunt, or jeer at someone or something happening on stream. The emote features a mischievous or taunting face, often interpreted as someone making a "boo!" sound to tease or express disapproval in a lighthearted way.
Origin
The exact origin of the boo emote is unclear, as it is not one of the original global Twitch emotes and does not have a widely documented history tied to a specific streamer. It appears to have gained popularity in the early 2020s, especially as a BetterTTV (BTTV) or FrankerFaceZ (FFZ) third-party emote. The image is often associated with meme culture and may be inspired by exaggerated emoji or cartoon faces used for playful taunting.
When to use
When a streamer fails at something or makes a mistake, viewers might spam boo to playfully tease them.
During moments of friendly competition or rivalry, viewers use the emote to mock the opposing side.
It can also be used when something unexpected or silly happens, as a way to join in on the fun and banter in chat.
