Twitter increased its character limit from 140 to 280 in 2017. The company announced the experiment on September 26, initially testing longer posts with a limited group of users. The full change rolled out to all accounts in November.
The original 140-character limit came from Twitter’s early relationship with SMS text messaging. Mobile messages were commonly limited to 160 characters, and Twitter reserved 20 characters for a username, leaving 140 characters for the post. That restriction helped create Twitter’s famously concise style.
Twitter said the 280-character expansion would help users express ideas without deleting words or splitting thoughts into multiple posts. The change was controversial because many users considered 140 characters an essential part of Twitter’s identity. Japanese, Chinese and Korean characters were initially treated differently because those writing systems can convey more information per character. A common mix-up is confusing the November 2017 expansion with later, much larger limits introduced for paid X subscribers.