Slime chunk finder
Type your world seed to see which chunks spawn slimes, using the same calculation as Minecraft Java Edition.
Your world
In game: type /seed in chat and click the number to copy it. Words work too, like in the world creation screen.
Nearest slime chunks
Map
Click a chunk to see its coordinates. Drag to move the map; with the keyboard, focus the map and use the arrows.
How slime chunks work
About one chunk in ten is a slime chunk. Which ones depends only on the world seed and the chunk position, so they never change. In a slime chunk, slimes can spawn below Y 40 in any light level, in every biome except mushroom fields.
Building a slime farm
Find a slime chunk near your base, dig out a room below Y 40 and light up every other cave nearby so slimes have nowhere else to spawn. Stand 24 to 128 blocks away so they can spawn and don't despawn. Several slime chunks next to each other make a much faster farm.
Swamps
Slimes also spawn on the surface of swamps and mangrove swamps between Y 51 and 69 in the dark, more often at full moon. That does not depend on slime chunks.
Bedrock Edition
Bedrock Edition uses a different calculation that does not depend on the seed, so this map is for Java Edition only.
About this tool
How do I find slime chunks?
Type your world seed (/seed in chat) in the slime chunk finder. The map shows every slime chunk; paste F3 + C to see the nearest ones to you.
At what height do slimes spawn in slime chunks?
Below Y 40, in any light level, in every biome except mushroom fields.
Does it work for Bedrock?
No. Bedrock Edition uses a different calculation, so this finder is for Java Edition.