Your starting point
Enable Slime chunks in the Overworld and zoom to 4 blocks per pixel or closer. Each square represents a 16 × 16-block chunk; it does not guarantee slime spawning.
In this guide
Comparison and grid boundaries
This numeric diagram illustrates chunk boundaries, not an example world. Rounding towards zero would put negative coordinates in the wrong chunk.
| Check | Java | Bedrock |
|---|---|---|
| Calculated pattern | Seed and chunk coordinates | Chunk coordinates; repeats across seeds |
| Changing the seed | Can change the pattern | Changes the world, not this pattern |
| What it does not prove | That slimes will spawn in your farm | That slimes will spawn in your farm |
- Chunk −2: blocks −32 to −17
- Chunk −1: blocks −16 to −1
- Chunk 0: blocks 0 to 15
- Chunk 1: blocks 16 to 31
What a slime chunk indicates
Minecraft has underground areas known as slime chunks; swamps are another habitat for slimes. Seeing a slime in a swamp does not by itself prove that you are standing in a slime chunk.
Source: Minecraft — Mob Menagerie: Slime
Check Java and Bedrock separately
In the calculation used by this map, Java combines the world seed with chunk coordinates. In Bedrock, the slime chunk pattern depends on chunk coordinates and repeats across seeds. Changing a Bedrock seed can therefore change the biomes without moving the slime squares.
Always select the correct edition. This overlay represents the pattern calculated by the website’s experimental engine; it does not observe mobs in your save or confirm a farm’s spawning conditions.
Enable and read the overlay
This guide’s button opens the Overworld with Slime chunks enabled at a zoom where the layer can be displayed. If you zoom out again, the selection stays enabled even when its squares stop being drawn.
- Confirm the edition and, for Java, your world seed.
- Under Structures, enable Slime chunks and zoom in if the zoom notice appears.
- Go to your base’s coordinates to inspect the surrounding area.
- Select a point to see its chunk coordinates and whether it belongs to the slime pattern. Copy the coordinates and check the area in the game.
Blocks and chunks use different units
A chunk covers 16 blocks along X and 16 along Z. Convert a block coordinate to a chunk coordinate by dividing by 16 and rounding down. This matters at zero: X = −1 belongs to chunk −1, not chunk 0.
For example, chunk X = −1 spans blocks −16 through −1, while chunk X = 0 spans 0 through 15. Apply the same rule to Z. A square in the overlay marks that whole footprint, not a single point where a mob must appear.
Before preparing a farm
Use the overlay to choose an area to investigate. Check your edition’s spawning rules, the available space and your world settings in the game before spending time excavating. A marker does not replace that check.
The map’s Y level controls the biome query; it does not enable or disable the horizontal slime chunk pattern. The coordinate grid also does not replace the green overlay: they are different visual aids.
If no squares are visible, first check your zoom, dimension and whether the layer is enabled. Nearby search is for structures and biomes; slime chunks are explored through their own overlay.
Sources and review
Game information checked against the linked sources. Map steps were checked in this preview; its predictions remain experimental.