What a mob spawner does and where to find one

A mob spawner is a cage-like block that automatically creates mobs — hostile creatures, animals, or other entities — in the area around it. You cannot craft one; spawners only appear naturally in the world inside dungeons, mineshafts, strongholds, and other generated structures. When you find one, it will be actively spawning one type of mob: zombies, skeletons, spiders, cave spiders, or blazes are the most common.

The spawner itself is a dark metal cage with a glowing mob model rotating inside. It will only work if you are within 16 blocks of it horizontally and 8 blocks vertically. If you move farther away, spawning stops. The spawner will not work in peaceful mode, and it will not spawn mobs if the light level in the spawning area is above 11.

Once you find a spawner, you cannot pick it up with any tool — not even a pickaxe with Silk Touch. If you break it, it disappears. To use a spawner, you must build a farm around it in place.

Key Takeaways

  • Mob spawners are found naturally in dungeons, mineshafts, and strongholds, and they spawn one type of mob repeatedly in a small radius around them.
  • You must keep the spawning area dark (light level 11 or below) and stay within 16 blocks horizontally to keep the spawner active.
  • A basic spawner farm needs a spawning chamber, a collection area, and a way to kill or move mobs to a killing station.
  • Water channels, fall damage, and suffocation are the most common methods to kill mobs automatically once they spawn.
  • Spawners work best in the Overworld; nether spawners like blaze spawners require different designs because blazes are immune to fall damage.

Building the spawning chamber around the spawner

Once you locate a spawner, clear out the surrounding area in a 16-block radius. Remove all blocks that could interfere with mob movement, and make sure no other mobs can spawn naturally by placing torches or slabs on all nearby surfaces. The spawner itself should sit in the center of a flat, open chamber.

Build walls around the spawner to contain the mobs. A simple box design works: create a room about 9 blocks wide and 9 blocks long, with the spawner in the middle. Leave the floor open or use half-slabs so mobs can spawn on it. Keep the ceiling at least 3 blocks high so mobs have room to appear. Make sure no light enters the chamber — cover all openings and use dark blocks like blackstone or deepslate.

The spawner will push newly spawned mobs away from itself, so they will naturally move outward toward the edges of the chamber. This is where you will direct them into collection channels.

Creating water channels to move mobs

Water is the most reliable way to move mobs from the spawning chamber to a killing area. Dig a channel 2 blocks wide and 1 block deep around the edges of your spawning chamber, sloping gently downward. Place water source blocks in this channel so the current flows toward your killing station.

Mobs will be pushed by the water current and flow along the channel. You can make the channel slope down multiple levels if you want to move mobs far away from the spawner. Water will not damage mobs, so they will survive the journey intact and arrive at the killing station alive.

If you are building a spawner for a specific mob type that is hard to kill (like blazes or endermen), water channels let you move them safely without triggering their special abilities. Blazes, for example, take damage from water, so a water channel can kill them slowly as they travel.

Setting up a killing station with fall damage

The simplest killing method is fall damage. At the end of your water channel, create a drop of 24 to 32 blocks. Mobs will take fatal fall damage at this height. Place water at the bottom of the drop so mobs land in it and die on impact, then collect their drops in a hopper below.

Build the drop shaft with solid walls so mobs cannot escape sideways. Make the bottom 1 block deep with water, and place a hopper underneath pointing into a chest. When mobs die, their drops will flow into the hopper and collect in the chest.

This method works for most mobs but not blazes or endermen. Blazes take no fall damage, and endermen will teleport away before hitting the ground. For those mobs, use suffocation instead: create a 1-block-high tunnel that mobs must crawl through, then push them into a solid block using a piston. The suffocation damage will kill them.

Collecting drops and optimizing your farm

Place hoppers at your killing station to funnel drops into chests or into a central storage system. Hoppers move items one at a time, so if your farm produces many drops quickly, use multiple hoppers or a hopper line to prevent items from despawning.

You can also use a hopper minecart on rails to collect drops more efficiently. Place the minecart above the killing area and run rails through it so items are picked up and transported to a distant storage location.

To increase farm output, you can build multiple spawning chambers around different spawners and funnel all mobs into a single killing station. This multiplies your drop rate without needing to stay near multiple farms.

Staying in range and managing the spawner

The spawner only works when you are within 16 blocks horizontally and 8 blocks vertically. Build an AFK platform — a safe spot where you can stand or sit without moving — at the edge of this range. This lets the farm run while you are away from your keyboard.

If you build the AFK platform too far away, the spawner will stop working. If you build it too close to the killing station, you might accidentally kill yourself or interfere with mob movement. A platform 12 to 14 blocks away from the spawner, at the same height, is usually safe.

Some players use a minecart or boat to AFK in place without moving, which prevents the server from kicking them for inactivity. Check your server rules before doing this, as some servers disable AFK farms.

Spawner farms for specific mobs

Different mobs require different designs. Zombie and skeleton spawners are straightforward — they take fall damage and drown easily. Spider spawners need taller drops (32+ blocks) because spiders can climb walls and may escape a short fall. Cave spider spawners are smaller and harder to farm efficiently because cave spiders are tiny and fast.

Blaze spawners in the Nether are the most complex. Blazes are immune to fall damage, fire, and drowning. You must use suffocation or a suffocation piston trap. Build a 1-block-high tunnel that blazes must crawl through, then push them into a solid block with a sticky piston. The suffocation will kill them, and their blaze rods will drop into a collection area below.

Endermen spawners are rare but possible. Endermen teleport when they take damage, so fall damage and suffocation do not work. Instead, use a water channel to move them into a dark room, then use a piston to push them into a 2-block-high space where they cannot teleport. They will suffocate and drop enderpearls.

Frequently Asked Questions

Can I move a spawner to a different location?

No. Spawners cannot be broken and picked up, even with Silk Touch. If you break a spawner, it disappears forever. You must build your farm around the spawner where you find it.

Why did my spawner stop working?

The most common reasons are: you moved more than 16 blocks away horizontally, the light level rose above 11, or you are playing in peaceful mode. Check that you are close enough, that the chamber is dark, and that the spawner is still active by watching for mobs to appear.

How much XP does a spawner farm give?

Spawner farms give very little XP because mobs killed by environmental damage (fall, suffocation, drowning) drop almost no experience. If you want XP, you must kill mobs yourself with a sword. Spawner farms are best for collecting drops like bones, arrows, and rotten flesh, not for leveling up.

Do I need to be awake for the spawner to work?

You need to be within 16 blocks for spawning to happen, but you do not need to be actively playing. You can stand on an AFK platform and let the farm run while you step away. Some servers disable AFK farms, so check your server rules first.

What is the best mob to farm with a spawner?

Zombie spawners are the easiest and most useful. Zombies drop rotten flesh (which can be turned into leather or fed to dogs), and the farm is simple to build. Skeleton spawners are also good because they drop bones and arrows. Avoid cave spider spawners unless you want string — they are small and hard to farm efficiently.