Block Outline FX is a client-side Fabric mod for Minecraft 1.21.4 that upgrades the vanilla block outline with fully configurable visuals.
Main Features
- Custom outline color (RGB + alpha)
- Through-walls outline mode
- Visual effects: rainbow, pulse, sparkle
- In-game vanilla-style settings screen
- Mod Menu config integration
- Hotkeys for quick access (
O) and enable/disable (K)
Compatibility
- Minecraft: 1.21.4
- Loader: Fabric
- Environment: Client-side only
Author
- aizero_o
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.21.4
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
Verified by MCModsHub
- Ships as blockfx-1.0.0.jar — drop this file into the mods folder
- Download size: 1.1 MB
- Download link checked 1 Sept 2026 — working
These come from our own check of the pack file, not from the source page.