Twitter became a publicly available service in 2006.
The platform originated within Odeo, a company working on podcasting products. Jack Dorsey proposed a service for sending short status updates, and the first version was tested internally before being spun out as a separate company called Obvious Corporation.
Twitter’s first public message appeared in March 2006, and the service was launched publicly later that year. Its initial appeal came from combining mobile text messaging with a simple public stream of updates. At first, it was much smaller and less visually elaborate than the later social network.
The year is sometimes confused with 2007, when Twitter received major attention at the South by Southwest Interactive festival. That event helped accelerate Twitter’s popularity, but the service itself had already become publicly available in 2006.