Sneaking

Sneaking (or Crouching) is a gameplay feature that prevents players from falling off of blocks, helps players hide from mobs, among other useful features.

Controls
On any PC system, the control for sneaking defaults to. The player sneaks as long as the key is held down. $$ with touch controls, sneaking is toggled by double-tapping the sneak button (the button with an open circle). $$ with a controller, sneaking is toggled by pressing on the right analog stick until it clicks. Certain actions like opening the inventory can cancel sneaking, even if the player is still holding down the key for sneaking.

Effects
While sneaking:


 * Players are prevented from walking off edges if the difference in height between the two surfaces is $5/8$ of a block or higher, which makes sneaking useful for building horizontally outward over empty space.
 * The player can still dismount blocks while sneaking by jumping over the block's edge.
 * A sneaking player still falls if the block beneath the player's feet is destroyed.
 * Players move slower, at a speed of about 1.31m/s.
 * Hostile mobs do not become aware of the player until within 80% of the usual detection range.
 * Eye level moves down $1/8$ of a block, and the character model bends over slightly. This can be viewed using.
 * The player's hitbox height reduces from its usual 1.8 blocks:
 * $$, the height becomes 1.65 blocks, allowing movement through spaces as small as 1.75 (2 - $1/4$) blocks high.
 * $$, the height becomes 1.5 blocks.
 * No footstep sounds occur.
 * In multiplayer, a sneaking player's name tag appears fainter than normal, invisible to players more than 32 blocks away, and invisible through solid blocks.
 * If players are on a ladder or vine, they do not move down. This gives the impression of holding on to that specific ladder rung or vine. Mining speed is still decreased by a factor of 5.
 * Players may place certain items and blocks on some block entities. For example, placing a hopper on a chest, a torch on a furnace, or redstone on a command block.
 * Players are able to interact with a horse when pressing control while holding the  key.
 * Sneaking prevents the player from bouncing on slime blocks, resulting in fall damage.
 * Magma blocks and Campfires do not cause harm.
 * Redstone ore does not light if stepped on by a sneaking player.
 * Sneaking causes a player to sink faster when submerged in water.

Sneaking does not affect:
 * Jump height: players can still jump up to the same heights and at the same vertical speed. Horizontal jump speed and distance is decreased, however.
 * Farmland and crops: they are still trampled when jumped upon.

Trivia

 * In creative mode, if the player holds the sneak button and then double taps the space bar to fly, they jump up and are stuck at the height they jumped up in and stay like that until they release the space bar. However, this isn't a bug because the sneak key is also the key used in flying to a lower altitude, so using both keys at the same time purposefully keeps the player still.
 * $5/8$, the player uses a sneaking stance when flying downward. The player can also place blocks on chests, furnaces and other utility blocks in this stance, suggesting the player is actually in a sneaking mode. $$, the player no longer enters sneak mode when flying downward, but they still don't interact with blocks by right-clicking.
 * $$, the player can bridge out by looking at the air block they are placing on, though it must be adjacent to an existing block. This works even if the player is not sneaking.
 * $$, the player must travel to the edge of the block (usually by sneaking) and look backward to place the next block.
 * If the player sneaks immediately after sprinting, they sneak faster than someone who sneaks without sprinting.