What was Twitter’s character limit for tweets before it doubled to 280 in 2017?

Twitter allowed 140 characters per tweet before raising the limit to 280 in 2017.

The limit came from Twitter’s early connection to SMS text messaging, where messages commonly had a 160-character maximum. Twitter reserved space for usernames, leaving 140 characters for the message itself. This constraint became one of the service’s defining features and encouraged concise writing.

On November 7, 2017, Twitter expanded the limit to 280 characters for most languages. Japanese, Korean, and Chinese users generally remained on a lower practical limit because those writing systems convey more information per character. The change was one of Twitter’s most significant product changes, although the original 140-character limit remained strongly associated with the platform.