Slime Summon Command Generator (Java Edition) — Custom Size NBT
Build /summon commands with custom NBT for every vanilla mob — baby variants, equipment, colors, and mob-specific options.
Run /summon from an operator’s chat, a command block, or the server console. Not every internal NBT field is covered — this generates the commonly-used ones for each mob.
How to Use the Slime Summon Generator
- Type slime into the search box, or open the page directly – it defaults to the Slime panel.
- Set the Size field to any whole number from 0 to 127. Vanilla naturally-spawned slimes only ever use 0 (small), 1 (medium), or 3 (big), but this generator lets you type in any value in that range for a custom-sized slime.
- Use the shared fields above the panel (Health override, Glowing, No AI, etc.) to adjust anything else.
- Copy the finished
/summoncommand into a command block, server console, or operator chat.
Command Syntax & NBT Reference
Base command: /summon minecraft:slime ~ ~ ~ {NBT}. The Size field maps to:
Size:<n>– a byte value from 0 up to 127 that controls both the slime’s physical size and its hitbox/damage scaling. Size 0 is the small slime, Size 1 is medium, and Size 3 matches the naturally-spawned “big” slime – anything else (2, 4, 10, 50…) is a size vanilla spawning never actually produces on its own, though the game fully supports it via this NBT tag.- This generator’s default value is
1(medium) if you don’t change the field.
Note that size directly affects jump height, movement speed, and contact damage – larger values make for a slower but harder-hitting slime, and very large sizes (like 50+) create a slime big enough to visibly dwarf normal blocks, mostly useful for builds, showcases, or joke encounters rather than balanced gameplay.
Frequently Asked Questions
What happens when a slime summoned with a custom Size dies?
A slime bigger than the smallest size still splits into smaller slimes on death, following the same rule as natural slimes – a big slime splits into several medium ones, and each medium slime splits into small ones. A slime already at the smallest size (0) doesn’t split further; it just dies.
Can I summon a slime bigger than the natural maximum size of 3?
Yes – this generator’s Size field accepts values well beyond the naturally-spawning range, up to 127. Vanilla world generation itself never spawns anything past size 3, but the /summon command and this generator both support the full NBT range.
Do slimes summoned this way still only spawn/behave correctly in slime chunks or swamps?
Spawning rules like slime chunks and swamp moon phases only govern where the game naturally spawns slimes on its own – they don’t apply to a slime you summon directly with a command. A summoned slime behaves and fights identically wherever you place it, regardless of chunk type or moon phase.
Is there a difference between Slime and Magma Cube besides where they spawn?
Magma Cube is a separate, fireproof variant found in the Nether that jumps higher and deals more damage than a same-sized Slime, and it doesn’t get bounced around by knockback the same way. Use the Magma Cube entry in this generator instead of trying to make a fire-immune Slime – that immunity isn’t something addable to the Slime entity via NBT.
Related Tools
- Magma Cube Summon Generator – the fireproof Nether cousin with the same Size mechanic.
- Effect Command Generator – buff or debuff a summoned slime with status effects.