Hollower

A simple Fabric mod for Minecraft that lets you easily select, highlight, and hollow out large builds.

Before/After hollow demonstration

What does Hollower do?

• Select an area: Mark two corners to define a box in your world.
• Cast: Instantly highlight all visible blocks inside your selection.
• Hollow: Remove the inside of your selection, leaving only the outer shell.
• Undo: Restore the last hollowed area if you make a mistake.
• Multi-level undo: Undo multiple hollow or cast actions, not just the last one.
• Fast and smooth: Designed for large builds and big selections.

Why use Hollower?

• Save time: No more breaking blocks one by one.
• Perfect for builders: Quickly create hollow structures, clear out interiors.
• Easy to use: Simple commands, no technical setup needed.
• Safe: Undo mistakes with a single command.
• Client-side only: No need to install on servers.

How to use

/hollower pos1 — Set the first corner of your selection (where you are standing).

/hollower pos2 — Set the opposite corner of your selection.

/hollower cast <depth> — Highlight all visible blocks in your selection. You can use this multiple times to add more blocks. (Optional: depth set how much layer to keep)

/hollower undocast — Undo the last cast action. Use this if you want to remove the most recently highlighted blocks.

/hollower clear — clear all the casted blocks.

/hollower unselect — remove selection and clear all casts.

/hollower hollow — Hollow out everything inside your selection, leaving only the outer shell.

/hollower undo — Undo the last hollow or restore action. You can use this multiple times to go back further.

Troubleshooting

• If the mod doesn't show up, make sure it's in your mods folder and you're using Fabric.
• For crashes or issues, please include your latest.log and any crash-reports when reporting a bug.