Twitter's headquarters are in the most populous US state.
California ( [ kælᵻˈfɔːrnjə , _ - ni.ə ] , ) is the most populous state in the United States and the third most extensive by area . Greater Boston is the metropolitan region of New England encompassing the municipality of Boston , the capital of the US state of Massachusetts , and the most populous city in New England , as well as its surrounding areas . Twitter . Twitter Inc. is based in San Francisco , California , United States , and has more than 25 offices around the world .