What is the biggest planet?
The biggest planet in our solar system is Jupiter, over 1200 times the size of earth however biggest planet discovered is TrES-4b, 80% bigger than Jupiter.
TrES-4 b is a gas giant exoplanet that orbits an F-type star. Its mass is 0.78 Jupiters, it takes 3.6 days to complete one orbit of its star, and it is 0.05084 AU from its star. Its discovery was announced in 2007.