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Mojang Dev Tools

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

Fabric
Loaders
Fabric
Downloads on Modrinth
201
Followers on Modrinth
4
version
1
Updated
May 29, 2026May 29
Published
in 2026
Example of Mob Brain and Villager Pathing debug · swipe

At a glance

Runs on Fabric
For Minecraft 26.1.2
Latest version — 1.1.5 from May 29, 2026
License GPL-3.0-or-later — free
Where it's needed
In gameunknownOn serverunknown

The author didn't say where the mod is needed

Game versions26.1.2

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)

HotkeyAction
F3 + ZCustom debug renderer menu
F3 + F6Mojang internal debug options menu
F3 + EChunk section path debug overlay
F3 + FToggle fog rendering
F3 + LToggle smart culling
F3 + OFrustum culling octree overlay
F3 + UFreeze/capture frustum at current position
F3 + VChunk section visibility overlay
F3 + WWireframe 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 `** — Visualize pathfinding routes in-world
  • **`/debugmobspawning at `** — 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)

FAQ

How to install Mojang Dev Tools?

Install Fabric for your Minecraft version, download Mojang Dev Tools for the same version and loader, put the file into the mods folder and launch the game with the loader profile.

Which Minecraft versions does Mojang Dev Tools support?

Mojang Dev Tools has builds for Minecraft 26.1.2.

License and source
GNU General Public License v3.0 or laterfree to use and share; changes to the mod itself must be published under the same license
Original — Modrinth↗Files unchanged, verified with SHA-512Is this your mod? For rights holders

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