【Minecraft】How to Use slime chunk tool (Slime Finder) | How to Check & Find Slime Chunks with Real In-Game Examples【Java / Bedrock】

This guide is for players who want to track down slime chunks.
I’ll walk you through how to use the slime chunk tool (Slime Finder).
Everything is explained for both Java Edition and Bedrock Edition.

Hi, I’m Yuzukaki.

“ I want to use way more sticky pistons, but I never have enough slimeballs…”
“ I’d love to build a slime farm, but I can’t even find any slimes in the first place…”

If you play survival for a while, you pretty much run into this at least once.

Collecting slimeballs is pretty tough, too

If you knew exactly where your slime chunks were, all of this would be solved—but the annoying part is that you can’t see slime chunks from inside the game UI.

So in this article, I’ve put together a step-by-step guide on how to use the slime chunk tool (Slime Finder) to locate slime chunks in your world.

After reading this, you’ll be able to:

Pinpoint the exact locations of slime chunks in your own world
Understand a workflow that works for both Java Edition and Bedrock Edition
Finally get rid of that “I don’t really get how the slime chunk tool (Slime Finder) works…” feeling
And as a bonus, keep a checklist for when slimes aren’t spawning properly

If this helps your world even a little, I’ll be really happy.

※This guide is based on Minecraft Java Edition 1.21.x and Bedrock Edition 1.21.x.

What this article covers:
1. Java Edition → Get your seed using /seed → plug it into slime chunk tool (Slime Finder) → dig the green chunk down to Y=39 or lower
2. Bedrock Edition → Check seed & coordinates from Settings → switch slime chunk tool (Slime Finder) to Bedrock → cut out a 16×16 area using the numbers
3. If nothing spawns, use the checklist in this article to review height / distance / spawn-proofing / biome / difficulty
This article was published as an English translation of a Japanese blog post.

1. What Is a Slime Chunk? Basic Rules & Spawn Conditions
2. What Is the slime chunk tool (Slime Finder)?
3. Prep: How to Check Your Seed and Coordinates [Java / Bedrock]
4. Basic How-To for the slime chunk tool (Slime Finder) Website (PC / Mobile)
5. Example: Using slime chunk tool (Slime Finder) to Dig Out and Confirm a Slime Chunk
6. Tips & Gotchas for Bedrock Edition
7. How to Find Slime Chunks Without Any Tools
8. Checklist for When Slimes Won’t Spawn
9. Summary

If you just want the quick how-to on slime chunk tool (Slime Finder), feel free to jump straight down to section 4!

1. What Is a Slime Chunk? Basic Rules & Spawn Conditions

Let’s quickly break down what a slime chunk actually is.
Once you get this part, all the info slime chunk tool (Slime Finder) shows you will suddenly make way more sense.

Slime Chunk Basics

Here are the rules that matter most:

The Minecraft world is divided into “chunks” that are 16×16 blocks each
Out of all those chunks, about 10% are designated as slime chunks
Inside a slime chunk, slimes can spawn if their feet are at Y=39 or lower
Slime spawns inside slime chunks ignore light level
However, they won’t spawn in certain biomes like mushroom fields or the deep dark

Once you dig into a slime chunk, slimes will suddenly start popping up from a certain depth

So basically:

“In a slime chunk, as long as you’re at Y=39 or below and you leave enough open space, slimes will spawn.”

That’s the core idea behind a classic underground slime farm.

Differences Between Java and Bedrock

Java Edition and Bedrock Edition handle this slightly differently, so it’s good to have the basics in your head.

Java Edition
- Which chunks are slime chunks depends on the world seed
- If you use the same seed and the same version, the slime chunks will be in the same places even if you recreate the world
Bedrock Edition
- The algorithm that decides slime chunks is different from Java
- Slime chunks aren’t seed-based, so the slime chunk layout stays consistent across worlds
- Your seed still matters for plenty of other things (and it’s useful to keep around), but for slime chunks the big key is: use a Bedrock-compatible map

Note: Bedrock slime chunks themselves don’t depend on the seed, but Chunkbase still asks for a seed for technical reasons.

Trying to figure out “which chunks are slime chunks” by hand with:

Chunk-level randomness
Plus the “Y=39 and below” rule

…is pretty brutal.
That’s where today’s main character, the slime chunk tool (Slime Finder), comes in.

2. What Is the slime chunk tool (Slime Finder)?

Here I’ll quickly explain what slime chunk tool (Slime Finder) actually is.

What the slime chunk tool (Slime Finder) Does

slime chunk tool (Slime Finder) is a web tool that shows you which chunks are slime chunks on a map.
If you’re looking for it, search for “Chunkbase slime chunk tool (Slime Finder)”.

Some key points:

For Java, you enter your world seed and you’re good to go
On the map, slime chunks appear as green squares
You can switch between Java Edition and Bedrock Edition
You can plug in X/Z coordinates to look for slime chunks specifically around your base

In other words, it’s a tool that “makes invisible slime chunks visible at a glance.”

Pros and Cons (My Honest Take)

Here’s how it felt after actually using it.
In short, it’s extremely powerful if you seriously want a slime farm in survival.
But yeah, it does feel a bit like cheating or spoilers, haha (more on that later).

◎ Pros

Deciding where to build your slime farm becomes ridiculously easy
No more blindly strip-mining underground “hoping” to hit a slime chunk
The overall way of thinking is similar for both Java and Bedrock

△ Things to Be Aware Of

If you enjoy pure “wander around and see what happens” exploration,
it might feel like too much of a spoiler
Once you get used to it, it’s tempting to just “tool-check everything,” so
it’s a good idea to set your own rules, like only using it on certain worlds

I was able to instantly say “This is it!” and find a slime chunk right next to my base

In this article, I’m writing with the assumption that:

“You’re playing on a survival world where you seriously want a slime farm, and you’re going to use slime chunk tool (Slime Finder) just enough to make that happen.”

I’ll keep the vibe to that level.

3. Prep: How to Check Your Seed and Coordinates [Java / Bedrock]

Before using slime chunk tool (Slime Finder), you need to know two basic things:

Your world seed
Your current coordinates (X/Z)

This section covers how to check both in Java and Bedrock.

3-1. Java Edition: How to Get Your Seed

For single-player Java, this is super easy.

Enter the world you want to check
Press the T key to open chat
Type /seed and run it
The number that appears on screen is your world seed

If you do that, your seed will appear like this (Java Edition)

On multiplayer servers:

Whether /seed is allowed
And what permissions your account has

…will decide whether you can see the seed.
If it doesn’t show, you’ll need to ask the server owner/admin for the seed.

On multiplayer, make sure you follow the server’s rules before asking for or using the seed!

3-2. Bedrock Edition: How to Get Your Seed

Bedrock doesn’t have a /seed command like Java. If you try it, you’ll usually get an “unknown command”–type error.

The easiest way is to open Settings → Game → Seed and copy it from there.

On my setup (PC Bedrock), it just gave me an error

The simplest method is:

While in the world, open the pause menu
Go to “Settings” → “Game”
Scroll down until you see the “Seed” field

The red circle here is pointing at the seed value (Bedrock)

The number shown there is your seed.
※You can see this whether cheats (commands) are on or off.

Note: On Bedrock Realms, the seed may not be visible—ask the owner/admin.

3-3. How to Read Your Coordinates (X / Z)

Java Edition

Press F3 to open the debug screen
On the left, you’ll see something like XYZ: …
- Example: XYZ: 123.456 / 64.000 / -789.123
- X and Z are your horizontal position

Note: On Java, If you can't align the coordinates properly, use the Block: coordinates on the F3 screen (integers) instead of manually trimming decimals—this avoids off-by-one mistakes, especially with negative coordinates.

Bedrock Edition

Go to “Settings” → “Game” → turn “Show Coordinates” on

Turn on the “Show Coordinates” option circled in red in the settings screen (Bedrock)

A line like Position: 100, 64, -200 will appear at the top left of your screen
Again, X and Z are horizontal; Y is height

If you see your coordinates at the top left of the screen, you’re good to go!

slime chunk tool (Slime Finder) only needs X and Z, so just jot those down.

3-4. Seeing Chunk Borders (Java Edition)

Because slime chunks are “chunk-based,” it’s very handy to know which chunk you’re standing in.

In Java, you can:

Press F3 + G to show the chunk borders as wireframe lines
Press F3 + G again to hide them

If you can see yellow and red lines showing the chunk borders, you’re all set.

When you build a slime farm, you typically:

Dig out one full slime chunk (16×16 blocks) that shows up as green in slime chunk tool (Slime Finder)

So leaving the chunk borders on makes it much harder to accidentally dig the wrong area.

4. Basic How-To for the slime chunk tool (Slime Finder) Website (PC / Mobile)

From here, we’ll go through the actual flow for slime chunk tool (Slime Finder).
※Because of copyright and terms of use, I can’t show screenshots of the site here, so please open slime chunk tool (Slime Finder) in another tab and follow along on your side.

4-1. Quick Tour of the Screen Layout

The slime chunk tool (Slime Finder) screen is roughly laid out like this:

Top: Seed / Version settings
Middle: Map with slime chunks drawn on it
Bottom: X/Z input boxes + GO button

On the map:

Green square tiles = slime chunks
Red circle (pin) = the coordinates you specified (like your base)

That’s the mental model.

4-2. Step 1: Enter Your Seed

First, enter your world seed.

(Java Edition) Use the /seed command to show the seed → write it down.

(Bedrock) Go to Settings > Game > Seed → write it down.

Paste the seed you found into the Seed field at the top
If you’re on Java, that’s all you need here
For Bedrock, you can type it in too—the slime chunk layout itself doesn’t change with the seed, but pasting your world seed is still a nice “keep everything consistent” habit (especially if you ever toggle biomes or use other map tools)

4-3. Step 2: Match the Version / Edition

Next, make sure your edition is set correctly.

In the Version (or Edition) dropdown:
- Choose “Java Edition” if you’re on Java
- Choose “Bedrock Edition” if you’re on Bedrock

※If you get this wrong, the slime chunk locations won’t match your world, so double-check it!

4-4. Step 3: Move the Map to Your Base Area Using X/Z

Once the seed and version are set, the map will fill up with green squares (slime chunks).

Now we want to zoom in on the area around your base using X/Z coordinates.

(Java Edition) Press F3 to show your coordinates → write them down.

(Bedrock) Settings > Game > turn on Show Coordinates > copy the coordinates from the top left.

In-game, stand where you want your farm (near your base) and note down the X/Z
On slime chunk tool (Slime Finder), enter those values in the X and Z boxes at the bottom
Press GO

The map will center around those coordinates, and you’ll be able to see all the slime chunks near your base in one go.

4-5. Step 4: Read the Slime Chunk’s Coordinates

Pick one nearby slime chunk and decide which one you’re going to dig out.

Click / tap a green square (slime chunk) on the map
On the side of the screen (bottom right on PC), you’ll see something like:
- From: (X1, Z1)
- To: (X2, Z2)
  These are the coordinates of the chunk’s four corners

That From to To range is one full chunk (16×16 blocks).

Example:

From: (160, 448)
To: (175, 463)

Then:

X = 160–175
Z = 448–463

…is your slime chunk.
Write those ranges down somewhere safe.

4-6. Step 5: Use Grid Lines to Make It Easier (Optional)

If you check Grid Lines, the map will show a grid overlay, making it much easier to see the chunk boundaries.

This helps when:

You want to see exactly where one chunk ends and the next begins
You want to get a feel for how far the chunk is from your base

I personally recommend keeping it on most of the time.

5. Example: Using slime chunk tool (Slime Finder) to Dig Out and Confirm a Slime Chunk

From here, let’s go through:

“Using slime chunk tool (Slime Finder) to locate a slime chunk and then digging it out in-game to confirm that it actually works.”

The focus here is just:

Confirming the chunk is real and slimes spawn there

…not building the final full farm.

5-1. Pick One Chunk to Dig First

First, I recommend starting with just one slime chunk near your base.

If it’s too far away, running back and forth gets annoying
If it’s directly under your main base, future build plans might end up overlapping

So something like:

“A slime chunk that’s close to your base but offset a little to the side”

…is usually easiest to live with long-term.

I was lucky and had a slime chunk right next to my base

👆Slime chunks are fairly common, so I recommend a location that’s not too far, but not directly under your main builds either.

5-2. Java Edition: Show Chunk Borders and Mark Out 16×16

On Java, you can lean hard on the built-in chunk display.

Enter the world and walk to the coordinates you picked
Press F3 + G to show chunk borders
Move so that your position lines up with the From / To coordinates you wrote down from slime chunk tool (Slime Finder)

I kept the coordinates on-screen and felt my way around like, “Is it here? Maybe here?”

Roughly, you can:

Stand on the corner at the smallest X/Z (the From corner)
Make sure the chunk border lines form a 16×16 square around you

Before you start digging, double-check the borders to make sure it’s really the slime chunk.

If you’re worried about messing it up, put marker blocks on all four corners before you start digging—that makes it much harder to lose track once you’re underground.

I started by marking out all four corners—I'd hate to realize later that I was off.

5-3. Bedrock Edition: Cut Out the Chunk Using Only Coordinates

Bedrock doesn’t have Java’s F3 + G chunk border display, so you’ll need to cut out the 16×16 purely using coordinates.

One way to do it:

Get the From: (X1, Z1) / To: (X2, Z2) from slime chunk tool (Slime Finder)
In your world, move to the block at X = X1, Z = Z1 and place a marker block
Then mark the other corners so that your area covers X1–X2 and Z1–Z2

Here's roughly how I place marker blocks.

※On slime chunk tool (Slime Finder), you only need the integer portions of the coordinates, so you can just drop the decimal parts. Remembering “ignore decimals” makes it less stressful.

5-4. Dig One Floor at Y=39 or Lower with a 3-Block-High Ceiling

To confirm your slime chunk, dig that chunk down to Y=39 or lower.

In the 16×16 area, dig out a space with a ceiling at least 3 blocks high
Y≈30 is a nice safe target
The walls, ceiling, and floor can be made of whatever block you like

Here's what it looks like with one chunk hollowed out to a height of three blocks.

The goal here is:

“Check with actual spawns that this chunk is really a slime chunk.”

So you don’t need to build the full trap yet—just enough to see slimes appear.

Small personal horror story
Once, I thought, “Let’s do a full surface-level quarry in this slime chunk!” and started going all-in.
No matter how much I dug, no slimes.
The reason? My coordinates were off from the very beginning.
Always confirm that slimes actually spawn before you commit to huge digging projects.

5-5. Lighting and Other Mob Spawns

Even though slimes spawn in slime chunks regardless of light level, other hostile mobs still use the usual light rules.

When I dug mine out, the underground was basically a zombie nest.

So it helps to:

Put Jack o'Lanterns / Glowstone / Sea Lanterns in the ceiling and walls
Light up the floor with torches or other light sources

That way:

You end up with a room where slimes are the main thing spawning, which makes testing much easier.

5-6. Where You Stand Matters (Spawn Distance)

Your player position is also important while you’re waiting for slimes.

Hostile mobs won’t spawn within 24 blocks of the player
In Java Edition, once they’re more than 128 blocks away, they can despawn very quickly

So:

Make a little AFK room about 24–30 blocks away from the spawning floor.
If there are tons of caves and mobs underground, going up to around 100 blocks away vertically can help reduce interference.

Note: Hostile mobs (including slimes) won’t spawn within 24 blocks of the player, and in Java most spawns fail outside 128 blocks of a player.

This is a screenshot from when I was actually checking if slimes would spawn.

In my case, there were so many caves below that I ended up AFKing about 100 blocks above the test floor just to reduce mob interference.

Also, Bedrock’s spawn rules are slightly different from Java, so keep that in mind.

Quick recap:

◎Java Edition

Hostile mobs don’t spawn within 24 blocks of the player
Past 128 blocks, they can despawn very quickly
→ AFKing 24–100 blocks from the slime floor tends to work well

◎Bedrock Edition

The spawn range depends on your simulation distance
With a simulation distance of 4 (common on Realms), mobs spawn roughly 24–44 blocks away
→ A safe bet is to AFK around 30–40 blocks from your slime floor

5-7. If Slimes Are Spawning, You’re in the Right Place

If you wait a bit and see that:

Green slimes start popping in regularly
You’re not seeing many other mobs, but slimes still keep appearing

…then you can assume it’s really a slime chunk just like slime chunk tool (Slime Finder) said.
On the flip side, if absolutely nothing spawns, that’s a red flag.

When I tried it the first time, nothing spawned and I was just like “???”

They were happily spawning in a cave in the neighboring chunk (my chunk alignment was off).

If slimes are happily bouncing around: congrats! Time to think about the actual trap.
From here, you can turn that test room into:

A lava-kill slime farm
An iron golem–based lure farm

…whatever matches your style and world.

Example: building an iron golem-based slime trap.

※Detailed slime farm builds are outside the scope of this article.

6. Tips & Gotchas for Bedrock Edition

Now let’s cover some Bedrock-specific points and differences compared to Java.

6-1. Slime Chunk Logic Is Different From Java

As mentioned earlier, Bedrock:

Uses a different formula from Java for deciding which chunks are slime chunks
So even with the same seed, slime chunk positions do not match between Java and Bedrock

slime chunk tool (Slime Finder) handles this properly:

Just set Version / Edition to Bedrock Edition, and it shows the Bedrock pattern

So please always double-check that you’ve switched to Bedrock if that’s what you’re playing.

6-2. Watch Your Simulation Distance

In Bedrock, the “simulation distance” setting controls:

Where mobs can actually move and tick
Where spawning and AI updates happen

This also affects slime farms:

Your slime floor must be inside your simulation distance
If your farm is too far from where you usually hang out, it basically never runs

So when picking slime chunks, I recommend:

“Stay within a handful to maybe a dozen chunks of your usual base area.”

That way, the farm naturally runs while you play.

6-3. The “I Can’t See Chunk Borders” Problem

Bedrock doesn’t show chunk borders like Java does.

So you’ll be relying on:

The From/To coordinates in slime chunk tool (Slime Finder)
And marking out a 16×16 area purely with numbers

Without visible chunk borders, I constantly felt like “Where even am I?”

If that feels shaky, you can:

Place marker blocks every 16 blocks to show chunk “stripes”
Or use a separate chunk-calculator tool to convert coordinates into chunk boundaries

Personally, I think the “marker every 16 blocks” method is the easiest.

My recommendation: drop marker blocks every 16 blocks in X and Z.

7. How to Find Slime Chunks Without Any Tools

If you’re thinking:

“I get that it’s convenient, but I’d rather not use external tools if I can avoid it…”

…there are some old-school ways to look for slimes.
I’ll mention two of them briefly.

7-1. Hunt in Swamp / Mangrove Swamp Biomes

The simplest approach is hunting slimes at night in swamp or mangrove swamp biomes.

In swamps (and mangrove swamps), slimes can spawn between Y=51–69 if the light level is 7 or lower, and the spawn rate depends heavily on the moon phase (most on full moon, none on new moon).

Around the full moon, slimes spawn like crazy just like this.

If you “just need some slimeballs right now,” this is perfectly fine:

Use this method to stock a small supply
Then later build a proper farm using slime chunks once you’re ready

7-2. “Marking by Hand” in Deep Caves

Another method—this one is very old-school and pretty grindy—is:

Find a large cave at Y=39 or below
Whenever you see a slime, mark the surrounding 16×16 area on the floor/walls
After you’ve seen slimes in the same 16×16 a few times, treat it as a “candidate slime chunk” and dig it out

To be honest, this method is basically just RNG (so yeah, I don't really recommend it).

If we’re talking pure efficiency, slime chunk tool (Slime Finder) wins by a landslide.
But if you enjoy that slow “trip and mark” exploration style, this could be a fun side project.

8. Checklist for When Slimes Won’t Spawn

“If I followed slime chunk tool (Slime Finder) exactly, why aren’t any slimes spawning…?”

In that case, run through this checklist from the top:

[ ] Are you digging at Y=39 or lower?
[ ] Is your spawn floor a space with at least 3 blocks of height? (big slimes are quite tall)
[ ] Is the distance to the player at least 24 blocks, and generally not too far past ~128 blocks?
[ ] Is the difficulty not set to Peaceful?
[ ] Are nearby caves and the surface spawn-proofed so that
the mob cap isn’t completely filled by other mobs?
[ ] Is the biome not a mushroom fields biome or some other special biome that blocks slime spawns?
[ ] In slime chunk tool (Slime Finder)’s Version, did you pick the correct Java/Bedrock option?
[ ] Did you type the seed correctly? (Especially on Java, where the seed determines slime chunks)
[ ] On multiplayer (Java), does the server’s seed actually match the one you entered?
[ ] Did you build the farm outside the area you’re usually in, so the chunks are almost always unloaded?

If none of that fixes it, try:

Checking slime chunk tool (Slime Finder) again to see if a neighboring slime chunk might be the real one
On Java, using F3 + G to re-confirm chunk borders and make sure your dig is truly one 16×16 chunk

In other words, tackle it from both sides:
“Is the position right?” and “Are the conditions right?”

In the end, I had to dig out the neighboring chunk all over again (painful…).

👆I ended up having to redo the neighboring chunk myself, so… yeah. Learn from my mistakes and take your time lining things up!

9. Summary

In this article, we went through:

“How to use slime chunk tool (Slime Finder) to accurately locate slime chunks,”

…covering both Java Edition and Bedrock Edition.

Let’s recap the main points:

Slime chunks are special chunks that make up about 10% of the world
In a slime chunk, slimes spawn at Y=39 or lower regardless of light level
By using slime chunk tool (Slime Finder) with:
- Your world seed (required on Java; optional for slime chunks on Bedrock, but still handy to keep consistent)
- The right edition/version (Java / Bedrock)
- Your base’s X/Z coordinates
  …you can instantly map all the slime chunks near you
On Java, using /seed and F3 + G makes the whole process very smooth
On Bedrock, you’ll need to grab the seed and coordinates from Settings and
cut out the 16×16 area using the numbers themselves
If slimes still refuse to spawn, walk through the checklist:
height, distance, difficulty, other mob spawns, biome, version, seed (Java), etc.

Once you’ve locked in a slime chunk,
slimeballs, sticky pistons, and slime blocks stop being a bottleneck.

From there, you can choose:

A swamp-style farm
An underground slime chunk farm

…whatever fits your world and your taste.

If this helped you take that first step toward building a slime farm, I’m really glad.
Thanks a ton for reading all the way to the end!

Update History

2026/02/16 First published

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