Minecraft mob grinder: the complete guide

How a mob grinder works

Every mob grinder rests on three parts: a spawning chamber, a transport system and a kill point. Mobs spawn in the dark on opaque blocks, so the spawning chamber is simply a dark room with solid blocks on the floor. The transport system (usually water) carries the mobs to a central shaft, where they fall to the bottom. Down there you finish them off yourself, or lava or cacti do it automatically.

The key rule: mobs only spawn between 24 and 128 blocks from the player. Closer than 24 blocks, they won't appear. Farther than 128 blocks, they despawn immediately. That range decides where you build the farm and where you stand while AFK.

Spawner grinder: the easiest start

If you found a dungeon with a zombie or skeleton spawner, you already have the foundation for an XP farm. A spawner creates mobs automatically while a player is within 16 blocks.

Step-by-step build

1. Expand the chamber - enlarge the room to 9x9x4 blocks with the spawner in the center. Light it temporarily with torches so mobs don't get in the way while you build.
2. Water channels - put water sources along one wall of the chamber. The flow has to push mobs toward a central opening (1x2 blocks) in the floor or wall.
3. Drop shaft - dig a vertical shaft 22-23 blocks deep. After a fall from that height, mobs land with half a heart left: one punch with your bare hand kills them, and you get the full XP.
4. Kill point - at the bottom of the shaft, build a narrow corridor (1 block wide) where you can see the mobs' legs. Under the floor, put hoppers connected to a chest for the drops.
5. Remove the torches - take down the temporary lighting and the farm starts working.

Dark room farm: scaling up

A dark room farm doesn't need a spawner. It uses natural spawning mechanics. You build large, dark platforms (ideally at Y=200 or higher), and mobs spawn on them naturally. The upside: you get a mix of mobs (zombies, skeletons, creepers, witches, spiders), which means a variety of drops.

Construction

A typical dark room farm has 4-8 platforms of 8x8 blocks, arranged around a central shaft. The floor is made of full, opaque blocks (cobblestone, stone). Every 20-30 seconds, water systems or pistons push the mobs off the platforms into the central opening. From there the mobs fall to the kill point, identical to the one in the spawner grinder.

Building high up (Y=200+) matters because it minimizes competing spawns in the caves below the farm. The fewer places mobs can appear outside the farm, the faster the platforms fill up.

A dark room farm produces less XP per minute than a spawner grinder (mobs spawn more slowly), but it gives you gunpowder from creepers, which is essential for firework rockets and for flying with an elytra.

Ways to kill mobs

How you kill the mobs affects whether you get XP and which drops you get.

Fall damage

A shaft of 22-23 blocks leaves mobs with half a heart. You finish them with one hit and get the full XP. This is the most popular method in XP-focused grinders. It is simple, cheap to build and reliable.

Lava blade

A thin layer of lava (controlled with signs or trapdoors) in the mobs' path. Mobs walk through the lava and lose health. The catch: if the lava kills a mob, you get no XP. Use this method only for farms built for drops, not for experience.

Cacti

Cacti on sand in the transport channel damage the mobs as they pass. A cheap method, but the cacti destroy some of the drops that land on them. Not ideal, but it works in the early game.

Swords with Looting III and Sweeping Edge

At the kill point, finishing mobs by hand with a Looting III sword noticeably increases drops. Sweeping Edge boosts sweep damage, so one swing can hit several mobs for real damage. This is the best method for XP farms where you do the killing yourself.

AFK spot: where to stand

Your position is critical to how well the grinder performs. You have to stand 24-32 blocks from the spawning platforms (mobs don't spawn closer than 24 blocks) and, at the same time, within reach of the kill point.

In a spawner grinder, stand at the kill point: a spawner only has a range of 16 blocks, so you have to be close anyway. In a dark room farm, the best AFK spot is above or below the platforms, 24-28 blocks from the spawning surface.

While AFK, make sure your character isn't sleeping and doesn't have any menu open. On servers, check whether there is an AFK timeout that will kick you. Some servers ban AFK farming, so read the rules.

Enderman farm: the king of XP farms

An Enderman farm in the End is by far the best XP farm in the game. It is simple to build, though it needs access to the outer End islands (after you defeat the Ender Dragon).

The mechanic is elegant: an endermite (a small bug that occasionally pops out of a thrown ender pearl) is a natural enemy of endermen. You put a named endermite on a pillar in the middle of the platform, and endermen from all around run toward it and fall off the edge. At the bottom (22-23 blocks lower), they land at the kill point.

To build one you need: lots of blocks (end stone or cobblestone), a named endermite (a name tag, renamed at an anvil, keeps it from despawning), and rails and a minecart (optional, to hold the endermite in place). An Enderman farm solves your XP problem for the rest of the game: one visit gives you as much experience as you need to fully enchant a set of tools.

XP farms compared

Start by building a spawner grinder: it is cheap and quick to build. Once you reach the End, building an Enderman farm is priority number one. A guardian farm gives you more prismarine than XP and requires draining an ocean monument, which is a project of several hours.