Player movement

Jumping is how players and mobs go up blocks. Players and most mobs can jump up 1 block at a time. Jumping is not needed for differences in height of 1/2 block or less. The default key for jumping is the space bar, which is also used for swimming. Jumping uses more hunger than walking. Sprinting and jumping is faster than normal sprinting, but it uses much more hunger.

Trivia

 * Jumping then holding the spacebar in Creative Mode is how you fly. Flying is an easy way to get around, as you can caver vast distances quickly.
 * The player (and most mobs) jumps exactly 1.250 blocks high. (Constant value in Minecraft decompiled source)
 * The Jump Boost status effect increases this to 1.836 blocks, and Jump Boost II increases it to 2.517 blocks.
 * Spiders jump to attack, but these jumps only raise them to a height of 1.153 blocks.
 * Slimes and Magma Cubes move only by jumping.
 * Magma Cubes' jump height depends on their size: 1.836, 2.517, and 4.154 blocks for tiny, small, and large respectively.
 * The number of jumps you make is recorded in Statistics.