What was the rank of a jester in medieval times?

Answer 1

Jesters were middle class people. In order to do their work, they could really not be serfs. But they could also not be members of the nobility.

There were quite a few middle class people in the Middle Ages, despite what some people would think. Anyone who was not working as a laborer for hire, and was not a member of the nobility, would have been middle class, and that would have included merchants, craftsmen, bakers, inn keepers, surgeons, attorneys, stewards, and so on. Jesters fit in with them.