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 hotkey
• 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.

Superflat Preset

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

When creating te

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.​^{[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 a Structure Block or the "/place" command.

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.

v t e Java Edition technical
General Concepts Block entity Coordinates Crashes [String] Loot context Mob AI Point of Interest Identifier Screenshot Statistics Telemetry Tick UUID JSON General format Data values Classic Indev Pre-flattening Data component format Predicate Entity format Map item format [NBT Compound / JSON Object] NBT format Particle format Text component format § Formatting codes Key codes Random sequence Structure file format Schematic file format World Heightmap Seed Anomalous Data version Legacy Spawn chunk Level format Anvil file format Chunk format Player format Point of Interest format raids.dat format Command storage format Scoreboard format Legacy Classic level format Classic server protocol Indev level format Alpha level format Zone file format Region file format server_level.dat format villages.dat format Generated structures format .minecraft client.jar version.json client.json command_history.txt launcher_profiles.json options.txt version_manifest.json hotbar.nbt format Server list format Tools F3 Debug screen hotkey renderer Developer Tools GameTest Debug properties Obfuscation map Sound Block sound type Closed captions sounds.json Commands Brigadier Functions All commands Launching Mojang API Microsoft authentication Quick Play Legacy Legacy Minecraft authentication Yggdrasil Protocol Protocol version Packets Data types Encryption Server server.jar server.properties Server requirements Whitelist Operator list Protocols Query RCON Server Management Protocol Legacy al_version Item format
Data pack Components pack.mcmeta Pack format Advancements Functions Item modifier Loot tables Predicate Recipe Damage type Chat type Enchantment Enchantment provider Painting variant Banner pattern Instrument Jukebox song Trial spawner configuration Mob variants Dialog Armor trim Slot sources Timeline Villager trade​[upcoming JE 26.1] Trade set​[upcoming JE 26.1] World Clock​[upcoming JE 26.1] Tag Block Item Function Fluid Entity type Game event Biome Flat level generator preset World preset Structure Point of interest type Painting variant Banner pattern Instrument Damage type Enchantment Dialog Timeline Potion​[upcoming JE 26.1] Villager trade​[upcoming JE 26.1] GameTest Test environment Test instance World generation Dimension Dimension type World preset Biomes Carver Configured feature Tree Placed feature Environment attribute Noise settings Noise router Density function Noises Surface rule Structures Structure set Template pool Processor list Structure templates Removed Configured surface builder Data packs Caves & Cliffs Prototype Data Pack Phantom Frames Tutorials Importing Creating Optimizing Command blocks and functions Repairing a world corrupted by a data pack Content Custom enchantments Custom paintings Custom trims World generation New dimension Custom structures
Resource pack Components pack.mcmeta Pack format Language Models Blockstates Items Sounds (sounds.json) Shaders Textures Atlases Aa Fonts Colormaps Texts Waypoint styles regional_compliancies.json Equipment Debug Missing font character Missing model Missing texture Tools Slicer Legacy Texture Ender Unstitcher Tutorials Creating Loading Models Sound directory