Hopper

A hopper is a block which moves items into and out of containers, unless powered by redstone. If an item falls into the top of it, it will store it in its own internal inventory of five item slots. However, if the hopper's output is attached to (or pointing at) a container with inventory slots, it will transfer items from its inventory to the inventory of the attached block (or cart). FK DIS

Connecting
A hopper has an output, which can face in any one of the cardinal directions, or down. When placed, its output end will face into the block it was placed against (it will ‘connect to’ the block).


 * A hopper will connect to the block at which you point, and only that block (it does not automatically connect to others).
 * If you destroy the block to which the hopper was connected, it stays pointing to the original location; this is useful for transferring into minecarts via their sides.
 * To get a hopper to connect to a block with an inventory, sneak (default ) and click the block.
 * If you place a hopper by clicking on the bottom face of the block, the hopper will not point up, but down instead, because you can't output upwards. Upwards transfer can be achieved by using a minecart with hopper and sending it up along a rail, or powering an upward-facing dropper with a clock circuit.

Behavior
If its output faces into a block or entity with an inventory (like a chest, another hopper, or a Minecart with Chest; see below for a full list), a hopper will transfer items from its own inventory to it at a rate of 2.5 items per second (one item every 8 game ticks, or 4 redstone ticks, or 0.4 seconds).

Hoppers cannot be moved by pistons. Despite not appearing as a solid block, attached blocks such as rails, levers, and redstone dust can be placed on top of hoppers (but not on their side).

A hopper can suck in item entities from above it, even if such an item is only ‘flying through’ that block, or sitting on a block which is not full height (e.g. slabs, soul sand, or carpet) immediately above the hopper. Unlike a minecart with hopper however, it will not suck up items sitting on a full block above it.

The hopper will also transfer items from the inventory of a container placed directly above it into its own inventory at the same rate it outputs items. Even if the hopper is drawing items from an inventory above it, and depositing it into another attached inventory, it will still transfer from the source inventory to the destination inventory at 2.5 items per second. This is because every 8 ticks, it first tries to pull an item from the inventory above it, and then tries to output an item.

When powered by redstone, the hopper won't take items from the inventories of blocks directly above it, put items into an attached inventory or suck up items from the environment. However, a hopper below it can still take items from its inventory and a hopper above or beside it can still put items into it. Powering hoppers to achieve this effect is commonly referred to as the hopper being disabled or deactivating the hopper and eliminates the significant amounts of lag that activated hoppers may cause by looking for item entities to suck up.

When a hopper is connected to the side of an object, a chest for this example, and there is another hopper directly underneath the first hopper, the bottom hopper has a higher priority. Whenever the hopper is outputting, an item in the first nonempty slot will be sent to the bottom hopper, and immediately after, another item (if there is any) from the first among the remaining nonempty slots will be sent to the chest. If you put a stack of items in the hopper, it will be divided evenly between the bottom hopper and the chest unless it is an odd number in which case the bottom hopper will get one more than the chest. If the hopper is initially empty and is taking input from another hopper sideways, all the items will go into the bottom hopper. If instead the hopper is being fed by another hopper above, then the items will be split evenly between the bottom hopper and the chest.

Testing with Comparators
If a hopper is the input to a redstone comparator, the comparator will output a redstone signal whenever there are any items stored inside the hopper. An empty hopper produces a power output of 0, a single item in a hopper produces a power level of at least 1, and the power level will increase depending on how you fill the 5 stacks of the hopper (see Redstone Comparator for precise values) to a maximum power level of 15 at 5 full stacks.

Whether a comparator will activate when a hopper is simply transferring items from its input to its output depends on its configuration. For example, if three hoppers are arranged vertically feeding into each other, so that they are both pulling items from the hopper above and pushing items into the hopper below, a comparator of the middle hopper will activate; but if the middle hopper is faced to the side and powered, so that items are moving through it only because the hoppers above and below are pushing and pulling items into and out of it, a comparator off the middle hopper will not activate.

Interactions
Hoppers can remove items from and place items into the following:
 * Brewing Stands
 * Hoppers above the brewing stand will fill the ingredient slot, while hoppers to the side will fill the potion slots. Unlike furnaces, a hopper placed under a brewing stand will empty the brewing stand immediately, whether the potions are complete or not.


 * Chests
 * Large chests are treated as a single unit; one hopper placed on a large chest will fill up the whole chest.
 * Hoppers can only remove items from or place items into a chest if it can be opened.


 * Dispensers / Droppers
 * Items can be removed from as well as placed in dispensers/droppers.


 * Furnaces
 * Items fed to the top of a furnace will fill the ingredient slot, items fed from any side will fill the fuel slot, and hoppers under the furnace will only take finished products (and emptied buckets from using lava as fuel). A hopper removing items from a furnace will not yield experience points.


 * Hoppers
 * Hoppers both pull items from containers above them, and push items to containers they are facing (including other hoppers). Thus a hopper above a hopper will both push items into the hopper below and have items pulled from it by the hopper below. To stop item transfer in a vertical stack, two adjacent hoppers in a column must be deactivated so that the top hopper isn't pushing down and the bottom hopper isn't pulling from above. When two hoppers are laid horizontally, only one hopper needs to be deactivated because the hoppers can only push, not pull. Similarly, when a horizontal hopper is stacked above another hopper, vertical transfer between these two hoppers only can be interrupted by deactivating the hopper below.


 * Minecarts with Chest / Hopper
 * Hoppers will fill minecarts with chests or hoppers if they are pointing at them and are not separated by another block. Hoppers can also take items from minecarts above them; rails can be placed directly on top of hoppers by aiming at a nearby block or holding the sneak key (default ), to make unloading stations. A hopper will not unload a minecart which is on a Detector Rail above the hopper, because the detector rail will power the hopper.


 * Trapped Chests
 * Identical to chests (see above), except that interaction is blocked while the chest is open, as it emits a redstone pulse and powers the hopper.

Hoppers cannot remove items from or place items into Ender Chests. They do not interact with them in any way.

Trivia

 * A real-life hopper is a type of chute used in industrial processes that incorporates a limited storage capacity.
 * Chickens can easily become stuck inside hoppers, and once inside are difficult to interact with, but still produce eggs. A hopper filled with chickens and attached to a dispenser with a clock circuit results in a compact automatic chicken machine.
 * Hoppers can also be used to make a lossless manual cobblestone generator without using redstone, as they collect the cobblestone immediately above them before it can fall into lava.