Component Stack Size overhauls inventory management in Minecraft 1.21+ by allowing previously unstackable or low-limit items to stack cleanly without breaking game mechanics. Built entirely on Minecraft 1.21’s modern Data Components system, items will only stack when their properties (effects, enchantments, stored items) match perfectly.
Features & New Stack Limits
Empty Shulker Boxes: Stack up to x8 (strictly checks that the box is completely empty)
Potions: Stack up to x4 (must have identical effects, duration, and amplifier)
Water Bottles: Stack up to x16
Ominous Bottles: Stack up to x8 (must match amplifier level)
Enchanted Books: Stack up to x16 (must have identical enchantments and levels)
Music Discs: Stack up to x16 (identical song track)
Goat Horns: Stack up to x16 (identical sound variant)
Armor Trims: Stack up to x16 (identical trim type)
Beds: Stack up to x16 (all colors)
Banners: Stack up to x64 (identical patterns)
Armor Stands: Stack up to x64
Signs: Stack up to x32 (same wood type)
Saddles: Stack up to x32
Minecarts: Stack up to x8 (standard empty minecarts)
Cakes: Stack up to x8
Bowls: Stack up to x64 (Empty) | x16 (Soups & Stews)
Books & Quills: Stack up to x16 (blank/unwritten only)
Ender Pearls: Stack up to x32
Snowballs & Fire Charges: Stack up to x32
Eggs: Stack up to x32
Dragon's Breath: Stack up to x32
Technical Info
Loader: Fabric
Minecraft Version: 1.21.x
Requirements: Fabric API
Safety: Fully multiplayer-compatible. Uses vanilla item validation so no items or NBT/Data Components are lost when merging or splitting stacks.

