FARM GUIDE · BELOW Y 40
How to Build a Slime Farm
A slime farm gives you endless slimeballs for sticky pistons, leads, and slime blocks. This guide shows how to build a simple slime chunk farm below Y 40 in Java Edition, step by step, plus a swamp farm option.
Slime chunk finderChunk calculator
Free guide for Java and Bedrock, written for Minecraft 1.21 and newer.
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About This Guide
Slimes spawn in special underground chunks called slime chunks, at any light level, below Y 40. A farm clears out the space inside those chunks, adds flat platforms for slimes to spawn on, and funnels them into a killing area while you stand nearby. It takes some digging, but the design itself is simple.
What You Need
- Your world seed, to find slime chunks
- Pickaxes (Efficiency helps) and lots of time for digging
- Slabs, building blocks, and torches
- Water buckets and signs or trapdoors
- Optional: an iron golem and magma blocks for automatic killing
Step 1: Find a Slime Chunk
Paste your seed into the slime chunk finder and pick a slime chunk near your base. Two or more slime chunks next to each other make a bigger farm. On Bedrock, slime chunks are the same in every world.
Step 2: Clear the Area
Dig out the full 16×16 chunk from Y 39 down as far as you want your farm to go. Use F3+G on Java to see chunk borders so you stay inside the slime chunk.
Step 3: Build Spawning Floors
Build flat floors across the chunk, with 3 blocks of air between them so large slimes fit. Use full solid blocks: slimes can’t spawn on slabs, glass, or carpet. Light the floors with torches to block other mobs. Slimes in slime chunks don’t care about light.
Step 4: Add a Collection System
| Design | How it works |
|---|---|
| Iron golem lure | Slimes walk toward a protected golem and fall into a water stream |
| Trapdoor edges | Open trapdoors at the floor edges trick slimes into falling |
| Magma block kill floor | Small slimes die on magma blocks, dropping slimeballs |
| Hoppers and chests | Collect the drops at the bottom |
Step 5: Light Up Caves Nearby
The hostile mob cap is shared. If caves within 128 blocks are dark, zombies and skeletons fill the cap and slimes stop spawning. Light up every cave in range, or build the farm far underground and spawn-proof the area.
Step 6: Find the Right AFK Spot
Stand 24 to 128 blocks from the spawning floors. Closer than 24, nothing spawns. Farther than 128, slimes despawn. A spot about 25 to 30 blocks away is ideal.
Swamp Slime Farm Alternative
Slimes also spawn in swamps between Y 51 and Y 69 at night, with more during a full moon. A swamp farm works without the seed but only at night and depends on the moon phase.
Related Minecraft Tools
Free tools that help with this guide:
- Minecraft Seed Map: the full map with every biome and structure
- Slime Chunk Finder: Slime chunks for Java & Bedrock
- Chunk Calculator: Block, chunk and region coordinates
Frequently Asked Questions
Why aren’t slimes spawning in my farm?
Check that you’re in a slime chunk, below Y 40, on full solid blocks, and 24 to 128 blocks away. Then light up nearby caves.
Does a slime farm work on Bedrock?
Yes. Use Bedrock’s slime chunks, which are the same in every world.
What are slimeballs used for?
Sticky pistons, slime blocks, leads, and magma cream.
How big should the farm be?
One full slime chunk with 3 to 5 floors is a good start.
Final Thoughts
A slime farm is just a cleared slime chunk with flat floors, a lure, and the right AFK distance. Find your slime chunk first, light up the caves, and the slimeballs will keep coming.
