Many free personality assessments are fun, but not really useful. It depends on what you are looking for. If the 'test' provides you with results but no way to use the information (no interpretation of your results, no debrief, no access to a trained consultant) then you have data with potentially no understanding, no context or no way to apply the results. Unless you can find the content and consultant on your own you have to consider what you will do with the results. Finding a 'test' that is based on well known personality constructs and not one that makes up it's own personality factors is generally a better idea. Look for tests that offer you information on how they were created and what they were validated with (if the results are repeatable and how well they measure what they say they are measuring).I use an on-line assessment tool for Jungian Personality type assessment called Typefocus.com - there is a free version and the option for a more detailed paid result. I have used this assessment for 8 years and find it's validity as good as any out there for measuring Jungian personality type (it uses the same jungian functions as the MBTI, against which it has been validated). The reason I use this assessment is that there is also a lot of data related to personality type available in general and many trained interpreters you can tap into once you obtain your results. I have assessed many, many on-line personality assessments over the years and there are a lot that you can have fun with and others you will find more useful.