The extent to which 262 adults, recruited from a U.S. university sample and Amazon’s Mechanical Turk, believed the identity of a 13-year-old boy or girl persona in an online chat room was examined. Sixteen undergraduate confederates (aged 19–38) followed 2 basic biographical sketches (“Amber” or “James”) and were instructed to “chat like a teenager” in 1-to-1 private chats. Confederates cycled through conditions in which they provided no age or gender information (control), stated age and gender, stated age and gender and provided a picture (attractive or average), or stated grade only. In all but the control condition, participants estimated the average age of their chat partner to be 13 to 14. Meanwhile, when confederates stated their age and gender, 83% to 88% of participants believed the confederate’s stated age, and 94% to 98% believed stated gender. When asked about cues used to discern age and gender, most participants (98%) used multiple cues, including stated age and gender, content cues, style cues, and picture. Moreover, natural language analyses showed that confederates used significantly fewer analytic and 6-letter words, and displayed less clout than the adults with whom they chatted, and confederates who used more analytic words were perceived as older. These findings contradict Lincoln and Coyle (2013) and suggest that even confederates who are not specially trained law enforcement agents are able to deceive others about their age and gender in online chat rooms. This has important implications for those conducting undercover Internet stings and those who prosecute those cases.