Underground Beacon
by Jauchlander
Underground Beacon lets a beacon stay active when it sits underground or indoors, using a Tinted Glass Block placed above it in place of a clear path to the sky.
What it does
Normally a beacon needs an unobstructed view of the sky to work. This mod changes that requirement: a beacon can be activated underground or indoors as long as an Underground Beacon Block sits directly above it, with any number of other blocks between the two. The block placed on top is the one the beacon checks, so the beam is drawn up to that point instead of climbing to the vanilla maximum height of 2048.
The mod is published for Fabric only, for game version 26.2, and requires Fabric API. Players need nothing extra to join a server that runs it, because the environment is server required with the client optional. Players who do install it see the shorter beam rendering, while players without it still see the beam activate. Source code and an issue tracker are public, and the code is open source under the MIT License.
Key features
Underground activation
A beacon activates underground or indoors when an Underground Beacon Block is placed higher in the stack than any other block.
Shortened beam
The beam is rendered only up to the Tinted Glass Block rather than to the full build height, which keeps caves and rooms readable.
Configurable blocks
Tinted Glass is the default Underground Beacon Block, and a data pack can add or replace blocks through the underground beacon tag.
Color-changing blocks
Stained glass and similar blocks placed above a beacon deactivate it, so the color-changing beam is not affected.
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
Who it’s for: Server owners who want beacons to work underground, and map makers building indoor or subterranean areas on Fabric 26.2 with the Fabric API installed.
How it compares
Beacon Blocker is a Fabric mod for 26.2 that works on either side, and neither side needs it, and it is open source under the MIT License. Small Netherite Beacons is Fabric-only for 1.21.4 – 26.2, requires both client and server, and is also open source under the MIT License. Underground Darkness covers Fabric, Forge, NeoForge and Quilt for 26.2 – 26.3 with server required and client optional, but it is not open source and is licensed under the GNU General Public License v3.0 only.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Underground Beacon | Fabric | 26.2 | Server required, client optional | 2026-08-12 |
| Beacon Blocker | Fabric | 26.2 | Client or server, optional | 2026-06-29 |
| Small Netherite Beacons | Fabric | 1.21.4 – 26.2 | Client and server | 2026-06-22 |
| Underground Darkness | Fabric, Forge, NeoForge and Quilt | 26.2 – 26.3 | Server required, client optional | 2026-10-11 |
Questions
Does Underground Beacon need Fabric API?
Does a player need the mod to see the beacon work?
Which block does the beacon check above it?
In the catalog
Underground Beacon is one of 29,952 Game mechanics mods on ModsFinder, and one of 19,630 Game mechanics mods for Fabric. 13,894 mods support Minecraft 26.2.
Similar mods
What the author says
Allows a beacon to be (and stay) active even if there is no clear path to the sky. No more digging holes to make a beacon work underground. To use a beacon underground/indoors without access to the sky, the player must place an Underground Beacon Block above it. The mod configures the Tinted Glass block by default…
Official listing
- Modrinth page
- modrinth.com/mod/underground-beacon
- Owner
- Jauchlander
- Published
- 2026-08-08
- Updated on Modrinth
- 2026-08-12
- Facts verified
- 2026-10-15