Light Level Overlay
by Nesuwu
With Light Level Overlay, a player sees the light level of each block as numbers drawn over the world, showing where mobs can spawn.
What it does
The overlay shows the light level of the surface block on screen, so a player can check where hostile mobs will appear before night. Each block is colored by its value: red for 0, yellow for 1 to 7, and green for 8 and above. The numbers render above foliage and can be read through grass, while blocks hidden behind walls are not drawn. Underwater mode marks spots where drowned can spawn.
Scan distance is set separately for horizontal and vertical range, and the update interval and cache refresh rate in milliseconds can be tuned. The cache keeps the frame rate steady when the scan covers many blocks. The mod is client-side only, so a server does not need it and players can join a server without installing it. Mod Menu is optional and gives access to the settings screen. Light Level Overlay is open source under the MIT License and is published for Fabric and NeoForge on 1.21.1 – 1.21.10.
Key features
Surface light levels
Numbers appear on the blocks a player can see, showing the light level of each surface block.
Color-coded values
Red marks level 0, yellow marks levels 1 to 7, and green marks 8 and above, so spawn-safe ground can be spotted at a glance.
Underwater spawn check
An underwater mode shows where drowned can spawn, which helps when planning a route through water.
Adjustable scan and cache
Horizontal and vertical scan distance, update interval and cache refresh rate can be changed to balance detail and speed.
Compatibility
Latest build for each game version and loader.
1.21.x9 of 9 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Optional 1
Use cases
Planning a night route
A player can read the numbers before dusk and choose a path through green ground, away from red and yellow spots.
Who it’s for: Players who build in survival worlds and want to see spawn conditions on the ground before mobs appear, and anyone who checks light levels while building.
How it compares
Light Level Simple is also client-side only and works on Fabric and NeoForge, with files for 1.21.9 – 26.3, but it is under All rights reserved and is not open source. Light Level 2025 is client-side only, open source under the MIT License and limited to Fabric, covering 1.21.5 – 1.21.8. Light Overlay is Fabric only, client-side only and not open source, and its files cover 1.21.6 – 26.3.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Light Level Overlay | Fabric and NeoForge | 1.21.1 – 1.21.10 | Client-side only | 2026-01-14 |
| Light Level Simple | Fabric and NeoForge | 1.21.9 – 26.3 | Client-side only | 2026-09-30 |
| Light Level 2025 | Fabric | 1.21.5 – 1.21.8 | Client-side only | 2025-09-14 |
| Light Overlay | Fabric | 1.21.6 – 26.3 | Client-side only | 2026-10-02 |
Questions
Does Light Level Overlay need to be installed on the server?
Which loaders does Light Level Overlay support?
Is Mod Menu required?
In the catalog
Light Level Overlay is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 15,569 mods support Minecraft 1.21.10.
Similar mods
What the author says
Shows light levels on blocks. That is it. That is the mod. Inspired by Light Level 2025 by dark-lion-jp. This is a standalone implementation, not a port, not affiliated. Bug reports go here, not there.
Official listing
- Modrinth page
- modrinth.com/mod/llo
- Owner
- Nesuwu
- Published
- 2025-07-31
- Updated on Modrinth
- 2026-01-14
- Facts verified
- 2026-10-15