What It Does
Light Overlay puts a light level overlay directly into your Minecraft world. Flip it on and the game marks the blocks sitting below the threshold where mobs can spawn. You stop guessing whether a corner of your base is actually lit well enough, and start seeing it. It's a focused tool built for one job, reading light levels, not a general lighting or building add-on.
The mod runs entirely on the client. There's nothing to install on a server, and it has no server-side component at all.
Who It's For
It suits anyone who spawn-proofs a build: survival players lighting up a base before bed, server admins checking public spawn areas, and map builders who want a fast visual read on lighting instead of pulling out F3 and doing the math by hand. If you've ever dropped torches around a room hoping they covered everything, this tells you whether they actually did, block by block.
Controls and Configuration
Toggle the overlay with a keybind, F9 by default, or run the /lightoverlay command from chat. Settings sit behind Mod Menu or the /lightoverlay config command, so you can change how the overlay looks and behaves without opening a config file by hand. Both the toggle and the settings menu are reachable in-game, so there's no need to leave your world to adjust anything.
Translations
The project has community translations beyond English, including German, Chinese (Simplified), Spanish, Hungarian, Japanese, French, and Portuguese. Some of these are marked complete and others are still being worked on, so coverage varies by language depending on which one you pick.
Support and Development
The developer takes feature requests and bug reports through the project's issue tracker, and states that most of them get addressed within about two days. Look, that's worth knowing if you run into a problem or want to request a change.
Compatibility
Light Overlay is built for the Fabric mod loader and its project page lists support for Minecraft 26.3 and 26.2. It's marked as a required mod on the client side, and server side support is unsupported, so it won't do anything useful installed only on a server.
License
The mod is distributed under the Creative Commons Attribution Non Commercial Share Alike 4.0 International license. On its project page it's listed under the Utility and Quality of Life category.
