Intelligence Quotient (IQ) tests have sparked curiosity for well over a century. From classrooms to corporate boardrooms, these assessments have been employed to gauge cognitive capabilities, identify potential talents, and guide long-term planning. As society continues to place a premium on analytical thinking and problem-solving, many people are eager to discover the nuances of their own intelligence. Amid a sea of online tests, distinguishing a credible assessment from a hastily constructed quiz becomes paramount. We seek rigor, transparency, and reliability in measuring intelligence, and that is exactly what a trustworthy online IQ test should deliver. Below, we explore the importance of valid cognitive assessments, examine factors influencing IQ, and highlight how test design can either enhance or compromise the user’s experience.