Double jump
A double jump is a type of jump that is performed by jumping twice in a row. Unlike a triple jump, executing a double jump does not require Mario to be moving.
Properties
A double jump has a height of between 136.5 and 312 units, depending on how long the jump button is held[1]. This makes it one of the shortest jump types in the game, and only marginally higher than a standard jump. Double jumps are primarily only used in speedruns to carry momentum forward, rather than gain height, since there are many other types of jumps that provide significantly more height.
If the player jumps a third time after landing a double jump, and Mario is still moving forward in the same direction that the double jump was initiated in, he will perform a triple jump.