The social media platform known for its 280-character message limit is Twitter. This microblogging platform allows users to share short updates or posts, known as "tweets." Initially limited to 140 characters, the character limit was expanded to 280 to enhance expression without compromising brevity. Twitter serves as a real-time communication tool, enabling users to engage in discussions, share news, and interact with followers, making it an influential platform in social media and public discourse.