Minecraft Slime Chunk Finder
Find slime chunks in Minecraft Java Edition from your seed. Drag and zoom the chunk map and see the 10 nearest slime chunks with distances and directions.
Enter your Java Edition world seed and your X and Z coordinates, and the finder draws every slime chunk around you on a map you can drag and zoom. It also lists the 10 closest slime chunks with distance and direction. Slime chunks are 16 × 16 block columns where slimes can spawn below Y=40 at any light level. Which chunks they are depends only on the world seed and the chunk position.
How to use the slime chunk finder
- In your world, type
/seedin chat and copy the number. You can also enter the word or phrase you used when you made the world. - Press F3 and note your X and Z block coordinates. Type them into the X and Z boxes and press Go to position.
- Green squares on the map are slime chunks. The yellow dot is your position and the yellow outline is the chunk you are in. The box above the map says whether that chunk is a slime chunk.
- Drag the map to move it. Zoom with the mouse wheel, by pinching on a phone, or with the − and + buttons. When the map has focus, the arrow keys move it.
- Hover over a chunk, or tap it on a phone, to see its chunk coordinates and the range of block coordinates it covers.
- Select a row in Nearest slime chunks to jump to it on the map. Distances are measured in a straight line from your position to the centre of each chunk.
What a slime chunk is
The Overworld is split into chunks of 16 × 16 blocks. Each chunk has chunk coordinates, which are the block coordinates divided by 16 and rounded down. Block X = −1 is in chunk −1, not chunk 0. About 1 in 10 chunks are slime chunks. Slimes can spawn in them below Y=40, so slime farms are built in deep caves or dug-out areas inside these chunks.
In Java Edition, the game works out whether a chunk is a slime chunk from the world seed and the chunk coordinates. It combines them into a number, uses it to seed Java's random number generator, and draws a whole number from 0 to 9. If it draws 0, the chunk is a slime chunk. Only the lowest 48 bits of the seed affect the result. The finder repeats this calculation exactly, so it matches the game for every chunk, including far away from spawn and at negative coordinates.
Number seeds and text seeds
If you typed a word or phrase as your seed when you created the world, the game turned it into a number. The finder does the same:
| What you enter | How the game reads it |
|---|---|
Digits, with an optional leading - or + (for example -4172144997902289642) |
Used as the seed directly, if it fits in a 64-bit number |
| A number outside the 64-bit range | Treated as text |
Anything else (for example Glacier) |
Converted with Java's String.hashCode(), giving a number between −2,147,483,648 and 2,147,483,647 |
Under the seed box, the finder shows the number it is using. If it doesn't match what /seed shows in game, check the seed for typos.
Slime spawning rules in slime chunks
- Slimes spawn in slime chunks only below Y=40, in the Overworld.
- Light level and weather do not matter. But the block a slime spawns on must not give off light level 14 or more.
- A slime needs a clear space of 2.08 × 2.08 × 2.08 blocks, so even small slimes can't spawn in a gap only 2 blocks high.
- Each spawn attempt in a slime chunk has a 90% chance to fail. In Java Edition, slimes spawn in groups of four.
- Like other hostile mobs, they don't spawn within 24 blocks of a player. They despawn instantly if no player is within 128 blocks.
- They don't spawn on Peaceful difficulty. They also don't spawn in mushroom fields or the deep dark, because no natural hostile mob spawning happens there.
Swamps and mangrove swamps are a separate source. There, slimes spawn at Y=51 to 69 in light level 7 or less, more often when the moon is close to full. The map doesn't show swamps.
Bedrock Edition
In Bedrock Edition, slime chunks are in the same places in every world and don't depend on the seed. This finder only works out Java Edition slime chunks. Don't use it for a Bedrock world.
FAQ
Do slime chunks change when Minecraft updates? No. The Java Edition formula uses only the seed and the chunk coordinates, so the same chunks stay slime chunks across versions. The finder uses the formula documented for the current version, Java Edition 26.3.
Why don't I see slimes in a slime chunk? Check that you're below Y=40, that there's open floor with 2.08 blocks of headroom, and that you're on Easy or harder. You also need to be at least 24 blocks away but within 128 blocks. Most spawn attempts fail, and other hostile mobs fill the mob cap in nearby caves, so lighting up or blocking off caves around your farm helps.
How do I check that the finder matches my world?
Stand in a chunk the finder marks green, dig a large room below Y=40, and wait at least 24 blocks away. Slimes should appear. If none appear after a while, double-check the seed with /seed.
Can I use a text seed? Yes. Type the exact text you used when you created the world, with the same capital letters. The finder converts it the way the game does and shows the resulting number.
Does it work on servers? Yes, if you know the server's seed. Many servers hide the seed, and without it you can't calculate slime chunks.