A mob spawner is a block that creates monsters or animals automatically when you're nearby

A mob spawner is a cage-like block that generates creatures — zombies, skeletons, spiders, or animals — in a set area around it. You find them naturally in dungeons, mineshafts, and strongholds. The spawner only works when you're within 16 blocks of it, and it stops spawning once the area reaches a certain number of mobs. Most players build spawner farms to collect drops (like bones, string, or gunpowder) without hunting manually.

You cannot craft a spawner from raw materials. You either find one underground or use commands to place one. Once you have a spawner, you can modify what it spawns and build a farm around it to collect drops efficiently.

Key Takeaways

  • Natural spawners are found in dungeons, mineshafts, nether fortresses, and strongholds — use a cave finder or mine systematically to locate them.
  • You can change what a spawner creates by right-clicking it with a spawn egg (in Creative mode) or using a command block to set the mob type.
  • Spawners only work when you stand within 16 blocks horizontally and 8 blocks vertically, so your farm design must keep you in that range.
  • A basic farm needs a dark chamber around the spawner, a water channel to push mobs downward, and a drop to damage or kill them.
  • Spawners stop creating mobs once 6 to 8 mobs of that type are nearby, so your farm must move or kill mobs fast enough to keep the spawner active.

Finding a natural spawner underground

The easiest spawners to find are in dungeons, which appear as small rooms with stone brick walls and a spawner cage in the center. Dungeons are scattered throughout the Overworld at any depth. Strip mining — digging long horizontal tunnels at Y-level 0 to 16 — will eventually expose a dungeon. Mineshafts also contain spawners (usually cave spiders), and strongholds near the End portal always have a silverfish spawner.

If you're playing on Java Edition, you can use a cave finder tool online to see where caves and dungeons generate in your world seed, then navigate to those coordinates. On Bedrock Edition, cave finders are less reliable, so strip mining or exploring ravines remains the most direct method. Once you find a spawner, mark it with torches or a waypoint so you can return to build your farm.

Setting up the spawner chamber

The spawner itself must stay in darkness for mobs to spawn. Place torches or other light sources everywhere except directly around the spawner cage. Mobs spawn in a 9×9×9 cube centered on the spawner, so you need a chamber at least that size with no light inside it.

Remove the original dungeon walls if they're in the way, and build a larger box around the spawner using stone or dirt. Leave the spawner cage itself untouched — breaking it will destroy it permanently (unless you're in Creative mode with a Silk Touch pickaxe). The chamber should be tall enough for mobs to fall or be pushed downward; most designs use a 3-block-high space so mobs can spawn but not escape upward.

Building a water channel to move mobs

Once mobs spawn, you need to move them toward a collection point. The standard method is a water channel. Dig a trench 1 block wide and 2 blocks deep leading away from the spawner, then place water at the top end. Water will flow downhill and push mobs along with it.

The channel should slope downward gradually or drop into a vertical shaft. If you want mobs to fall straight down, dig a 1×1 shaft below the spawner and let water push them into it. Mobs will fall and take damage; you can either let them fall far enough to die or add a damage source at the bottom (like a suffocation trap or fall damage from a greater height). Test the water flow with a bucket before spawning mobs — water that doesn't flow properly will jam up your farm.

Collecting drops or killing mobs automatically

At the bottom of your farm, you have two choices: kill mobs automatically or collect them alive. For automatic killing, a 24-block fall will kill most mobs in one hit (except for Endermen and Wither skeletons, which need more). Dig a shaft 24 blocks deep below your water channel, and mobs will die on impact.

Alternatively, use a suffocation trap: push mobs into a 1×1×1 space using pistons or water, and they'll take damage from being crushed. Hoppers placed below the killing zone will collect all drops automatically and funnel them into a chest. This method works for any mob type and is faster than waiting for mobs to fall.

Staying in range while the farm runs

The spawner only works when you're within 16 blocks horizontally (and 8 blocks vertically) of it. If you leave that range, spawning stops. Most players build an AFK (away from keyboard) platform 16 blocks away from the spawner, where they can stand and let the farm run while they do something else. Place a bed or block to stand on at that distance, and the spawner will keep producing mobs.

If your farm is in the Nether, be aware that Nether spawners (like those in fortresses) have different mob types and may require different drop heights. Wither skeletons need a 32-block fall to die in one hit, so adjust your shaft depth accordingly.

Changing what the spawner creates

If you want to change the mob type a spawner produces, you need either a spawn egg (in Creative mode) or a command. In Creative mode, hold a spawn egg for the mob you want (like a Zombie Spawn Egg or Creeper Spawn Egg) and right-click the spawner cage. The spawner will now spawn that mob type instead.

In Survival mode, you'll need a command block. Place a command block next to the spawner and enter the command: /setblock ~ ~ ~ spawner{SpawnData:{entity:{id:"minecraft:zombie"}}}, replacing "zombie" with any mob ID (like "skeleton", "spider", "creeper", or "cow"). set up the command block with redstone, and the spawner will change. This method requires cheats to be enabled in your world settings.

Frequently Asked Questions

Can I move a spawner to a different location?

Not in Survival mode — breaking a spawner destroys it. In Creative mode, use a Silk Touch pickaxe to mine it and place it elsewhere. If you want a spawner farm in a specific location, either find a natural spawner nearby or use a command block to create one at your chosen spot.

Why did my spawner stop working?

The most common reasons are: you're too far away (more than 16 blocks), there's too much light in the spawner chamber, or too many mobs are already nearby. Add more torches around the spawner to check light levels, move closer, or kill the mobs already in the area to let the spawner resume.

What's the difference between a spawner farm and a grinder?

A spawner farm uses a natural spawner block to generate mobs. A grinder is a trap that kills naturally spawning mobs in a large dark area. Spawner farms are more efficient because you control exactly where mobs appear, but grinders work anywhere and don't require finding a spawner first.

Do spawners work in the Nether and End?

Yes, but Nether spawners (in fortresses and bastions) spawn different mobs like Wither skeletons and Piglins. End spawners are rare and spawn Endermen. The mechanics are the same — darkness, proximity, and mob cap limits — but you may need to adjust drop heights or collection methods for different mob types.

How many mobs can a spawner create at once?

A spawner stops spawning once 6 to 8 mobs of that type are within its range. The exact number depends on the mob type. Your farm must kill or move mobs faster than the spawner creates them, or it will jam up and stop producing drops.