Java developer tools

Developer tools are tools used by Mojang Studios developers to develop new features and debug glitches.

A number of debug tools are available during normal gameplay:

• The debug screen is a screen that can be enabled using the F3 key. It shows various values useful for debugging the state of the game.
• Debug hotkeys are key-combinations that trigger or enable debugging features.
• Debug renderers are a set of graphical tools used for technical analysis of Minecraft.
• GameTests are a system used to systematically test gameplay features.

Using special JVM properties (command line arguments when starting the game) many additional debug features can be enabled:

• Additional debugging commands
• Additional debug hotkeys
• Additional debug renderers
• Many other debugging tools (see debug properties)

Some features, while part of the code, can only be enabled using mods.

In most cases, mods can achieve this by overriding the IS_RUNNING_IN_IDE flag in the SharedConstants class.

The "Create Test World" button on the title screen can be used to generate a superflat world that is designed to be used for testing.​^{[more information needed]} The world is set to allow commands and uses Creative as the default gamemode. It also disables the generation of structures, and changes some game rules.^[1]

In Java Edition 26.2, the button was moved to right of the Singleplayer button and the label was changed to "TW".

Superflat Preset

minecraft:bedrock,3*minecraft:stone,116*minecraft:sandstone;minecraft:desert

Game rules

advance_time

false

spawn_mobs

false

advance_weather

false

The GameTest feature contains a hidden functionality that allows users to export data to an SNBT file.^[2]​^{[more information needed]}

Sub-commands

The following sub-commands are available on both singleplayer and multiplayer:

• /test export

• /test exportclosest

• /test exportthese

• /test exportthat

Test Instance Blocks

If the functionality is enabled, the "Export Structure" option will appear in the GUI for the Test Instance Block.

SNBT Files

Structure data that has been exported to an SNBT file is able to be loaded across different worlds. This can be done using the "/place" command or a Structure Block.

For example, to place a structure that has been exported to an SNBT file named "cookies", the following command can be used:

• /place template minecraft:minecraft/structure/cookies

In the video below, a YouTuber named EightSidedSquare showcased most of the developer tools before they were made available with debug properties.