MensaIQ.com, IQtest.com, Test-IQ.org, FunEducation.com, BrainMetrix.com and ClassicIQQuiz.org offer free adult IQ tests. The tests are similar, but they do tend to vary in length, style and content.
MensaIIQ.com offers a free online IQ test for adults with answers. The test consists of 39 varied types of questions. IQTest.com also offers a private, free IQ test. This test is designed to, according to the website, assess one's intelligence in 13 different areas to reveal the key strengths and weaknesses of the individual.
Test-IQ.org claims to be the most accurate online IQ test. The test consists of 20 questions and was created by the BMI IQ research team. This test also allows users to acquire an IQ certificate and performance report.
FunEducation.com offers a simple, Ph.D certified IQ test. According to the website, this test analyses the user's level fo cognitive abilities such as spatial reasoning and word analysis. This is predominantly a verbal IQ test with some spatial testing involved. For those wishing to find out more about themselves, Fun Education also offers personality tests and career quizzes.
BrainMetrix.com provides a free online IQ test which consists of 20 multiple-choice questions. Brain Metrix also offers games to sharpen the mind and increase the brain's agility.
ClassicIQQuiz.org has another simple, free IQ test. The site also features general information about IQ tests, such as how to improve one's score, what to expect when taking an IQ test and the history of IQ tests.