Stef Solari, also known online as JustStef (@iamjuststef), is an American content creator, singer and actress with Argentine family roots. She first gained popularity on TikTok through short-form videos, particularly lip-sync content, before expanding her presence across YouTube, Instagram and Twitch. Alongside social media, Stef has pursued a career in music, releasing pop singles such as “Miss U Miss Me,” “Liar Liar,” “Joke” and “February.” Her music includes both English and Spanish-language releases, reflecting her connection to her Argentine background. She also streams on Twitch, where she describes herself as a content creator, singer, actress and nighttime streamer.