Hollower
by lukebrl
Hollower lets builders select a box and strip out its interior, leaving only the outer shell of a build on Fabric for 1.21.11.
What it does
A builder marks two corners to define a box in the world, and the mod instantly highlights every visible block inside that selection. Removing the interior leaves only the outer shell, which speeds up hollowing large structures compared with breaking blocks one by one. Undo covers several levels, so a hollow cast can be reverted step by step, and the last hollowed area can be restored if a mistake was made.
Hollower is a simple Fabric mod for Minecraft that targets builders working on large builds with big selections. It needs Fabric API to run. The mod is client and server, so the server and every player need it. Only the 1.21.11 game version is covered, with 1.0.0 for 1.21.11 as the latest file, published 2026-03-18. The code is public and the mod is released under the Creative Commons Attribution Non Commercial 4.0 license, so it is not open source.
Key features
Two-corner selection
A box is defined by marking two opposite corners in the world, which sets the area that will be hollowed.
Visible block highlight
Blocks inside the selection that can be seen are highlighted at once, so the interior can be checked before removal.
Shell-only removal
Removing the inside of a selection leaves only the outer shell in place, which is the main purpose of the tool.
Multi-level undo
Several hollow actions can be undone in sequence, and the last hollowed area can be restored after a mistake.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Hollowing large builds
Builders clear out the interiors of large structures while keeping their walls and roofs intact.
Who it’s for: Builders who work on large structures and need to clear interiors quickly, often on multiplayer servers where the mod is installed on both sides.
How it compares
MagPix Builder is a Fabric option for 1.21.11 that is client and server and under All rights reserved, so it is not open source. Undo This is a Fabric, Forge, NeoForge and Quilt mod for 1.21.11 – 26.3 that is server required and client optional, under the MIT License, and its source is open. Hollower differs by limiting its files to 1.21.11 and its license to Creative Commons Attribution Non Commercial 4.0.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Hollower | Fabric | 1.21.11 | Client and server | 2026-03-18 |
| MagPix Builder | Fabric | 1.21.11 | Client and server | 2026-04-27 |
| Undo This | Fabric, Forge, NeoForge and Quilt | 1.21.11 – 26.3 | Server required, client optional | 2026-09-26 |
Questions
Does Hollower require Fabric API?
Does Hollower have to be installed on the server?
Which game versions does Hollower support?
In the catalog
Hollower is one of 36,990 Utility mods on ModsFinder, and one of 25,772 Utility mods for Fabric. 19,862 mods support Minecraft 1.21.11.
More from lukebrl
Similar mods
What the author says
A simple Fabric mod for Minecraft that lets you easily select, highlight, and hollow out large builds. /hollower pos1 — Set the first corner of your selection (where you are standing).
Official listing
- Modrinth page
- modrinth.com/mod/hollower
- Owner
- lukebrl
- Published
- 2026-03-18
- Updated on Modrinth
- 2026-03-18
- Facts verified
- 2026-10-15