Take any single die (or coin, or other object that should yield a uniformly-distributed set of random values). Roll it, and enter each value in the box below, one value per line. As you add more values, the page will try to guess the type of die that you're using and keep track of how many more values you need. Once you add in enough values, you'll see stats about the object's fairness.
Huge thanks to this answer from the RPG Stack Exchange; this implementation is heavily based on it. Also thanks to the jstat library for providing the chi-squared CDF function.
A project by John Ellmore. Contribute on Github.