CurseForge · Minecraft mod
Mojang Dev Tools
Unlocks the Mojang Development tools, useful for mod devs and players looking to understand more about the game!
Quick answer
Which Mojang Dev Tools release should I use?
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.
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.
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.
- 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.
- 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.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 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

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.
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
DevFlags 1.1.5
devflags-fabric-1.0.0.jar
29 May 2026
Looking for an older file? The official CurseForge project page is in Resources.