How to fix a Slime Spawner that is not working in Minecraft?

Updated to 1.20

Slimes are a key part of Minecraft that can be found in specific biomes and underground caves. Many players have reported that their Slime Spawners are not spawning in their Minecraft world, and it can be quite frustrating. If you’re one of these players, stick around till the end to know the reasons behind this issue and what you can do to get Slimes to spawn in your game.

What is a Slime Spawner?

Slime Spawning is the process of Slimes coming to life. An area where you can have Slimes spawning is incorrectly called a Slime Spanwer (it is not properly a Spawner because there are no Spawners involved. To know more about Spawners, you can check How to find ALL Mob Spawners in Minecraft).There are two ways Slimes can spawn.  They can naturally spawn in Swamp biomes, but only between layers 51 and 69 and the light level must be in 7 or less. If these conditions are met, Slimes will have a chance to spawn in the Swamp biome.

slime spawning in swamp

Slimes can also spawn in specific Slime Chunks in the Overworld, below layer 40, regardless of how much light is available. To locate Slime chunks in the game, you can use external tools such as AMIDST. These tools can help you identify the locations of Slime chunks in your Minecraft world.

slime spawning in slime chunk

It is to be noted that Slimes will not spawn within a certain radius of a player. This radius is 24 blocks. Moreover, they will begin to despawn if there is no player present within 32 blocks radius. This radius is 128 blocks in Java Edition while in Bedrock Edition this radius can be anywhere between 44-128 blocks.

Reasons for Slimes not spawning in Slime Chunks

There are several reasons why Slimes may not be spawning in Slime Chunks, such as:

  • Incorrect Chunk: Slimes will spawn only in certain chunks. Check your chunk with external tools like AMIDST to know if Slimes can spawn there or not.
  • Incorrect Difficulty: Slimes will only spawn in worlds set to “easy”, “normal”, or “hardcore” difficulty. If the difficulty is set to “peaceful“, Slimes will not spawn.
  • Overpopulation: If there are already a large number of Slimes in the area, they will stop spawning until the population decreases.

Steps to take to solve the issue in Slime Chunks

As we have already learned the reasons behind Slime not spawning, resolving this issue now becomes easier. So, let’s see what you can do when facing this problem in the game. 

Check your Difficulty setting

One of the first things to check is your difficulty setting in Minecraft. Slimes will only spawn when the difficulty is set to “easy or higher.” If you have it set to “peaceful” then Slimes will not spawn in your world. You can change the difficulty in the options menu or by typing “/difficulty [difficulty]” in the commands.

minecraft difficulty settings

Check your chunk

Slimes will only spawn in certain chunks in Minecraft. In Minecraft, Slimes only appear in certain chunks. Each chunk is a 16×16 area of the world that can load or unload depending on the player’s position. If no Slimes appear, it may be due to the chunk not being a Slime chunk.

To see the chunk that you are in, you can press F3+G. It will look like this:

chunk border

To know more about chunks and how they work, you can check How to reload Chunks in Minecraft?.

Once you’ve found a Slime chunk, the next step is to find a suitable place to build your farm. The farm should be built in an enclosed area with a ceiling.

After that, you need to build the actual farm. There are a few different designs that you can use, but the most important thing is to make sure that the farm is large enough to spawn multiple Slimes.

When the farm is built, all you need to do is wait for the Slimes to spawn.

Check your version

Finally, make sure that you’re running the latest version of Minecraft. Newer versions of the game may fix bugs related to Slime spawning, so it’s always a good idea to keep your game up-to-date.

Reasons for Slime not spawning in Swamps

There can be a variety of reasons why Slimes are not spawning in Swamps. A reason could be that the Swamp is too small. Slimes will only spawn in swamps that are at least 50 blocks wide. They only spawn with a light level of 7 or less, often on a full Moon, and never on a new Moon. Finally, make sure the Swamp is on ground level (51-69 included): Slimes will not spawn on slopes or in caves.

Steps to solve the issue in Swamps

Now that we know why Slimes wouldn’t spawn in Swamps, it will be much easier to solve the problem.

Check your biome

Slimes will only spawn in Swamps in Minecraft (on the surface at least). If you’re not seeing Slimes spawning, then it’s possible that the biome you’re in doesn’t support Slime spawning. Make sure you’re in a Swamp biome to ensure there’s a chance for Slimes to spawn.

To see what biome you are in, press F3.

f3 check biome

If you can’t find any Swamp, you can try to use the /locate biome command. To use commands you will need to have cheats allowed in your Minecraft world. If cheats are not allowed in your world, there is a workaround. You can check here how to still use cheats in that Minecraft world.

To use locate biome you just need to open the commands and type:

/locate biome minecraft:swamp

And you’ll see a message appearing with the coordinates ot the closest Swamp.

minecraft locatebiome

Now what you have to do to get there is just closing the gap between your coordinates (that you can see by pressing F3) and the coordinates of the biome that you want to go to.

minecraft coordinates
F3 coordinates

Another good reason to find Swamps is the Clay Diamond Trick.

Check your light level

Slimes to spawn, the light level in their spawning area must be 7 or lower. You can press F3 to check the current light level.

f3 check light level

To know more about light level and how to manipulate it, you can check Torch spacing: how to do it efficiently in Minecraft?.

Check the time and the Moon

Although Slimes can spawn every night (since there is a light level less than 7), they spawn more often on a full Moon. Check that there is not a New Moon, otherwise Slimes will not spawn.


Slimes not spawning in your Minecraft world can be a frustrating problem to encounter. However, with the right knowledge and understanding of how Slimes work, you can identify the potential cause of your issue and take the appropriate steps to fix it. First identify if you are in a Swamp or in a Slimes Chunk, then behave accordingly. Thank you very much for reading the article this far and I hope I’ll see you again around here. See you and take care!