As of 2015, a good location to find free personality tests is the HumanMetrics website. The tests on the site are categorized by age groups.
The free tests offered on the HumanMetrics site is based on Isabel Briggs Myers and Carl Jung's approaches to different personalities. The tests are straightforward, easy to follow and provided in multiple-choice answer formats. Users should pick the statements that they most agree with for each question. After the test is completed a personality profile is provided.
Another good site for free personality tests is Keirsey. The tests on this site are tailored after the Keirsey Temperament Theory. The personality test is comprised of an estimated 70 questions and is available in five languages. Test results are private and will not be shared with third parties. Users must provide a valid email address to receive their results.