CullTag

True Server-Side Nametag Culling for Fair Play

Vanilla Minecraft gives every player a free, built-in wallhack: nametags visible through solid blocks. CullTag fixes this unfair advantage with highly optimized, server-side raycasting.

If a player is hiding behind a wall, their nametag is gone. It’s that simple.

Because all calculations and packet interceptions happen entirely on the server, your players don't need to install anything. They can connect with a 100% vanilla client and immediately experience fairer gameplay, making it perfect for SMPs, PvP arenas, and hardcore survival servers.

Key Features

Zero Client Setup: 100% server-side. Vanilla and modded clients both see the correct, culled nametags automatically.
Engineered for Performance: Raycasting can be heavy, so CullTag is built to protect your server's TPS. It utilizes symmetric LOS (calculating only one ray per pair of players instead of two) and only runs a sweep every few ticks — typical cost is well under a millisecond.
Crouch to Hide: Crouching players have their nametag hidden from everyone entirely, regardless of line of sight — great for staying unseen. Enabled by default and fully optional.
Live Configuration: Tweak maximum tracking distance, tick frequency, and crouch-hiding in config/culltag.properties.
Hot-Swappable: Toggle the entire system or reload config changes live without ever needing to restart your server.
Built-in Profiling: Monitor exactly how the mod is operating under the hood with built-in performance metrics.

How It Works

Every few ticks, the server quietly casts a ray between each pair of online players. If that ray intersects with a block, the server intercepts the vanilla network packets and hides the target's nametag from the viewer. The exact moment a player steps out of cover and Line of Sight (LOS) is restored, the server updates the packet and the nametag seamlessly reappears.

When crouch_hides_nametag is enabled (the default), a crouching player's nametag is hidden from everyone outright — no line-of-sight check needed.

Commands

Manage the mod entirely in-game (requires appropriate permissions):

/culltag enable & /culltag disable — Toggle the culling system live. Your choice automatically persists to the config file.
/culltag reload — Hot-reload any changes made to culltag.properties.
/culltag stats — View real-time raycast performance metrics and active tracking data.

Requirements

Environment: Server-side ONLY (Drop it in your server's mods folder and you're done)
Dependencies: Fabric API

Known Incompatibilities

PassableFoliage — mutates leaf collision shapes on both client and server, desynchronising LOS raycasts through foliage and producing erratic nametag visibility.