Ten-Item Personality Inventory (TIPI)
Ten items, one minute: a rough outline of where you sit on the Big Five.
About this scale
The TIPI sketches the five Big Five traits with ten pairs of adjectives. It is the most widely used ultra-short version in research and takes about a minute. With only two items per trait, the result is a rough outline rather than a precise measurement; for a fuller picture, take the site's longer Big Five test.
SourceGosling, S. D., Rentfrow, P. J., & Swann, W. B., Jr. (2003). A very brief measure of the Big-Five personality domains. Journal of Research in Personality, 37(6), 504–528. The author's page states: “WANT TO USE THE TIPI? GO AHEAD. ANYONE CAN USE IT FOR ANY PURPOSE. NO NEED TO ASK ME FOR PERMISSION.”