Are there any known planets that are bigger than our sun?
The largest known planet is probably KOI-13b, which has a diameter just over twice that of Jupiter.
The previous record holder was WASP-17b, which has a diameter just under twice that of Jupiter.
A possible larger planet is HAT-P-32b with a diameter 2.037 times that of Jupiter, but this may be a brown dwarf.
Since Jupiter has a diameter about
Basically, beyond a certain mass gas giants start undergoing fusion reactions and become brown dwarf stars. Note I say mass - not diameter. As mass increases the density tends to increase too and smaller brown dwarfs tend to be similar in size to Jupiter.