Debug Block Collision Overlay Reloaded

Debug Block Collision Overlay Reloaded

A client-side mod that adds a new F3 debug overlay showing you exact block collisions, for 1.12.2.

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84 Downloads
forgeutility
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Screenshots

Overlay Vanilla Blocks Screenshot
Original Mod Logo
Mod List Screenshot
Current Logo Render

About this Mod

Debug Block Collision Overlay Reloaded

Vanilla Block Overlay Showcase

A client-side mod that adds a new F3 debug overlay showing you exact block collisions.

About

Original Mod's Github - Original Mod's Curseforge

Curseforge Page

Features

  • Toggleable overlay, default keybind F3 + O.
  • Multiple overlay modes, default keybind F3 + I.
  • Config file which allows you to set the overlay mode, the level of chat feedback and line rendering settings.
  • In-game configuration through Forge that is dynamicly reloaded.
  • Has been tested with Cleanroom Loader (0.4.2-alpha) and Celeritas.

Usage

The main way to interact with this mods is by using the F3 + KEY keybinds which by default are F3 + O to toggle the overlay on/off and F3 + I to change the overlay mode.

There is also a config file which is dynamicly reloaded and can be edited in game or on the main menu.

Why

Well working on ProjectE-Charms I had to create some custom collision for a block but was having trouble visualizing the boxes so I looked on curseforge for mod that would help me do that, I ended up on Debug Block Collision's Curseforge so I downloaded it. After I had used it for a little bit on the Cleanroom Mod Loader I noticed a few main issues:

  • The keybind handling had broken debouce (actually a Cleanroom issue with modifier keys).
  • Toggling modes was clunky since there was only one keybind.
  • And the text and formatting could do with some improvement.

All of this inspired me to improve this mod by adding a second keybind, improving Cleanroom compatibility and rewriting the lang file; so I did.

Modpacks

You don't need to ask permission or anything to use this in your modpack.

Issues

If you notice an issue and want to make me aware please report them on the project's Github issues tab.

Available Versions

Debug Block Collision Overlay Reloaded 2.1.1release
MC 1.12.2forge
February 4, 2026
Debug Block Collision Overlay Reloaded 2.1.0release
MC 1.12.2forge
January 30, 2026

How to Install Debug Block Collision Overlay Reloaded on Your Server

1

Order Server

Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).

2

Set forge Loader

In the panel under "Egg", select the forge loader and matching Minecraft version (1.12.2).

3

Install Mod

Open the mod browser in the dashboard and search for "Debug Block Collision Overlay Reloaded". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.

Compatibility

Mod Loaders

forge

Minecraft Versions

1.12.2

Server-side

Unsupported

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Debug Block Collision Overlay Reloaded server crashes on startup – what to do?

Most common cause: wrong forge version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.12.2). You can switch loaders with one click in the panel.

Is Debug Block Collision Overlay Reloaded compatible with forge?

Debug Block Collision Overlay Reloaded officially supports forge for Minecraft 1.12.2. The Mado dashboard automatically detects incompatible loader combinations.

Server lagging with Debug Block Collision Overlay Reloaded – how to optimize performance?

Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Debug Block Collision Overlay Reloaded consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.

Rent Modded Server

Install Debug Block Collision Overlay Reloaded with just one click on your server.

Recommended RAM
4 GBab €8/mo
Min. 3 GB | +1 GB pro 8 Spieler
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NVMe SSD Storage
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Details

License
The Unlicense
Server-side
Unsupported

Supported Versions

1.12.2