LiteGrid

LiteGrid is a tiny spawn-proofing helper. It draws a 3×3 grid in the bottom-right corner showing the block light level of the floor tile you’re standing on and the eight tiles around you, so you can tell at a glance whether mobs can spawn here.

What you see

• Nine cells in a 3×3 grid, each showing a number from 0 to 15 — that block’s light value.
• Cell colors:
• Green — block light ≥ 8 (well-lit, mob-safe).
• Amber — block light 1–7 (some light, dim).
• Red — block light 0 (hostile mobs can spawn here at night).
• A white outline marks your own tile.
• A footer says either Spawn-proof or Mobs spawn: N/9 so you know if the area around you is safe to leave unlit overnight.

Use it for

• Spawn-proofing your base, mob farms, or paths between buildings — instantly see the gaps your torches don’t cover.
• Quickly checking a cave area before AFK’ing.
• Teaching new players where mobs spawn and why torches matter.

Features

• One key to toggle the HUD on/off (default L, raw GLFW polling — same key works on every supported MC version).
• Hides automatically when you press F1.
• Reads the block light component (the part that matters for mob spawning), not the sky component — so a daylit grass field still shows red, accurately predicting what happens at night.
• Pure client-side — install on the client only, works on any server, no cheats, no game state changes.
• Tiny render cost — nine block-light lookups per frame and a few rectangles.

Compatibility

Works on Minecraft 1.21.8, 1.21.9, 1.21.10, and 1.21.11 (Fabric Loader 0.16+). One JAR for all four — install via Fabric, drop into your mods/ folder.

Why not just press F3?

F3 shows light at your eye position only, packed in among 40 other debug values. LiteGrid shows the spatial spread around your feet — exactly what you care about when placing torches — without covering half your screen.