Mass Block Breaker — a Fabric mod for Minecraft 1.21.1 that lets you perform massive world-editing operations with a simple two-step confirmation system.
How it works: Break a block, kill an entity, or scoop a liquid once to see a count of all matching targets nearby. Perform the same action again within a few seconds to confirm and execute the operation. Every action can be fully undone.
Three core systems:
/massbreak — Block Operations
- Destroys every block of the same type within a configurable radius (up to 500)
- Chain Mode — Only destroys connected blocks (flood-fill vein mining)
- Replace Mode — Replaces broken blocks with another block instead of removing them
- Flatten Mode — Removes all blocks above a target Y-level and fills holes below with your chosen fill block
- Timelapse Mode — Dissolves blocks layer-by-layer outward from or inward toward the player, great for video recording
- Wave Mode — Breaks blocks in expanding rings with a configurable tick delay between rings
- Preview Mode — Highlights all affected blocks with glowing particles before you commit
- Configurable drops, processing speed, and max block limits
/masskill — Entity Operations
- Kills all entities of the same type within a configurable radius
- Safety Filters — Individually toggle protection for named entities, tamed pets, baby mobs, villagers, and other players
- Toggle loot drops and XP separately
- Full undo respawns exact copies with NBT data preserved
/massliquid — Liquid Operations
- Drains all water or lava within a configurable radius
- Triggered by using an empty bucket on a liquid source
- Source-Only Mode — Removes only source blocks; flowing liquid drains naturally
- All-Liquid Mode — Removes sources and flowing blocks together
- Also detects bucket fills (picking up liquid triggers the removal prompt)
Safety & controls:
- Built-in blacklists for blocks (bedrock, spawners, portal blocks, command blocks, jigsaw, etc.) and entities (ender dragon, wither, warden, iron golems)
- Configurable max operation size and blocks/entities processed per tick to prevent lag
- Confirmation timeout prevents accidental triggers
- Operator permission level 2 required by default (configurable)
- Undo history stores up to 10 operations per player per category
