Back to mods
Mojang Dev Tools project artwork

CurseForge · Minecraft mod

Mojang Dev Tools

Unlocks the Mojang Development tools, useful for mod devs and players looking to understand more about the game!

Choose a version Pick your version below, then grab the matching file.

Quick answer

Which Mojang Dev Tools release should I use?

Updated 2 months ago
Latest stable file DevFlags 1.1.5
Game version 26.1.2
Loader Fabric

Mojang Dev Tools DevFlags 1.1.5 targets 26.1.2 with Fabric. The project page does not say whether this file belongs on the client, dedicated server, or both. No extra mods listed for this file.

Where it goes

Is Mojang Dev Tools required on the client, server, or both?

The project page does not say whether this file belongs on the client, dedicated server, or both.

Client Source doesn’t say
Dedicated server Source doesn’t say
Loader for this release Fabric
Required install it here Optional supported, not mandatory Not supported do not install here Source doesn’t say do not assume

The source does not explicitly classify this release as client-only or server-only.

What else does Mojang Dev Tools DevFlags 1.1.5 need?

DevFlags 1.1.5. Change the file and its required mods may change too.

No extra mods listed for this file

This file does not list any required mods. Do not add a library just because a different file uses it.

This file does not list any required or optional mods.

Before you install it

Add Mojang Dev Tools without breaking your instance.

Built for Mojang Dev Tools DevFlags 1.1.5. Pick another file and the loader, install side or required mods may change.

  1. 01

    Stick to this file

    Use DevFlags 1.1.5. It targets 26.1.2 with Fabric; another release may have different loader, side or dependency requirements.

  2. 02

    Bring the mods it needs

    This file does not list any required mods. Do not add a library just because a different file uses it.

  3. 03

    Put it on the correct side

    The project page does not say whether this file belongs on the client, dedicated server, or both.

  4. 04

    Pick the file you checked

    Use the “Get this file” button beside DevFlags 1.1.5. It opens that exact file at the source.

About this project

What does Mojang Dev Tools add?

Mojang Dev Tools

Brain and Path Example

Unlocks all hidden developer features normally only available inside Mojang's IDE — with an in-game config menu to toggle each flag individually. ALL TOOLS EXIST IN OFFICIALLY RELEASED MOJANG BINARIES, THIS MOD SIMPLY ENABLES THE FLAGS

Sets SharedConstants.IS_RUNNING_IN_IDE = true and MC_DEBUG_HOTKEYS=true at class-load time, enabling debug overlays, internal commands, and dev-mode keybinds that are shipped in the game but never exposed in production.


Requirements

  • Minecraft 26.1.2
  • Fabric Loader 0.19.2 or later

Key Features

Debug Keybinds (F3 held)

Hotkey Action
F3 + Z Custom debug renderer menu
F3 + F6 Mojang internal debug options menu
F3 + E Chunk section path debug overlay
F3 + F Toggle fog rendering
F3 + L Toggle smart culling
F3 + O Frustum culling octree overlay
F3 + U Freeze/capture frustum at current position
F3 + V Chunk section visibility overlay
F3 + W Wireframe rendering mode

Note: F3+F with this mod enabled toggles fog instead of cycling render distance — this is the dev-mode override.


Renderer Overlays

Toggle any of these in-game via F3 + F6:

  • Pathfinding route overlay
  • Block neighbor update overlay
  • Structure bounding box overlay
  • Mob brain & memory overlay
  • AI goal selector overlay
  • Point of interest (POI) overlay
  • Bee hive/path overlay
  • Raid state overlay
  • Village section overlay
  • Entity hitbox overlay (integrated server)
  • Block collision shape overlay
  • Sculk catalyst spread overlay
  • Breeze mob debug overlay
  • Experimental redstone wire update order overlay

World Generation Debug

  • Cave carver volume overlay
  • Ore vein bounds and type overlay
  • Aquifer cell boundary overlay
  • Per-chunk feature placement count heatmap
  • Large dripstone cluster overlay
  • Disable individual world gen passes (fluids, aquifers, surface, carvers, structures, features, ore veins, blending, retrogeneration)

Gameplay & QOL Flags

  • All villager trade tiers unlocked immediately
  • Ignore mob cap on integrated server
  • Open worlds from incompatible versions
  • Allow simulation distance below the normal minimum
  • Keep jigsaw blocks after structure generation
  • Structure edit mode
  • Save structures as SNBT text files
  • Per-tick timing monitor
  • Show all sound subtitles
  • Suppress outbound Mojang telemetry
  • Cursor position in F3 overlay
  • Suppress all world saves (world reverts on exit)

Internal Server Commands

Unlocked when IS_RUNNING_IN_IDE is active:

  • /raid — Force-start/stop raids, set omen level, spawn raid captains, toggle raider glow
  • /debugpath to <x> <y> <z> — Visualize pathfinding routes in-world
  • /debugmobspawning at <x> <y> <z> — Diagnose mob spawning per category
  • /warden_spawn_tracker — Read/write warden warning levels for nearby players
  • /spawn_armor_trims — Spawn all armor trim combinations on armor stands
  • /serverpack push/pop — Push/pop server resource packs to clients without restarting
  • /chase — Sync camera between two game instances (Mojang QA tool)

Project description from CurseForge.

Pick your setup

Mojang Dev Tools by Minecraft version and loader

Choose the version and loader you play, then open the matching release.

1 available setups

Check the dependencies, then try the file in a copied instance before changing a world you care about.

Recent files

Mojang Dev Tools versions and loaders

1 of 1 releases match

Looking for an older file? The official CurseForge project page is in Resources.