How Data Packs Work in Minecraft: Setup and Installation

Key Takeaways

Point	Details
Data packs are folders	Data packs are folders or .zip files with a pack.mcmeta file that define game content like advancements, loot tables, and functions.
You can add data	You can add data packs when creating a new world (More tab > Data Packs) or manually by placing them in .minecraft/saves/<world>/datapacks.
Most non-experimental changes can	Most non-experimental changes can be reloaded with the /reload command; experimental features require rebooting the world or server.
Data pack load order	Data pack load order is visible in the Data Packs screen and can be modified; files with the same path in later packs override earlier ones.
If a data pack	If a data pack causes errors, Safe Mode disables all custom packs so you can still open the world and fix the problem.

What Exactly Is a Data Pack?

Data packs are a way to change how Minecraft works without modifying the game files themselves. Introduced in the very first snapshot of Java Edition 1.13, they give you the power to add or override almost any data-driven part of the game.

As explained in the official release notes:

Data packs Like resource packs, but for loot tables, advancements, functions, and structures.

A data pack can be either a folder or a .zip file that contains a pack.mcmeta file at its root. Inside, you organize content under a data folder, followed by a namespace folder (using only lowercase letters, numbers, underscores, hyphens, and dots). The namespace folder then holds subfolders for specific content types like functions, loot_tables, advancements, and structures.

Structure: pack.mcmeta, data folder containing a namespace folder determining the namespace of its contents.

A namespace should only contain the following symbols: 01​​234​5​6​78​9abcdefghijklmnopqrstuvwxyz-_.

Installing a Data Pack on a New World

The easiest time to add data packs is when you first create a world. On the "Create New World" screen, click the More tab, then the Data Packs button. This opens a menu where you can drag and drop your data pack files directly from your file explorer.

Data packs can be added to a world during world creation in the Create New World screen in the More tab by clicking the Data Packs button.

This menu allows drag-and-drop of data packs from a file explorer.

Once you've added your packs, you can also adjust their load order by dragging them up or down. This is important because if two packs define the same file, only the one in the later (lower) position takes effect.

Adding Data Packs to an Existing World

Already have a world you love? You can still add data packs after creation by placing them in the correct folder. Navigate to your .minecraft/saves/<world>/datapacks directory and drop the pack there.

Alternatively, data packs can be added to an existing world by manually placing them in the .minecraft/saves/<world>/datapacks folder of a world.

If the world is currently loaded, you'll need to use the /reload command to apply most changes. However, some additions—especially those involving new dimensions, world generation, or other "experimental" features—require you to exit and reopen the world (or restart the server).

When adding or modifying a data pack while the world is loaded, changes done to registry tags, loot tables, recipes, advancements, item modifiers, predicates, functions, and structure templates can be loaded using the /reload command.

Other features require the world or server to be rebooted for changes to take effect (see § Experimental Settings).

Managing Load Order with the /datapack Command

You don't need to fiddle with folders to change the order of active data packs while the game is running. The /datapack command lets you list, enable, disable, and reorder packs on the fly. This is especially useful for server admins who want to test different combinations without restarting.

This order can be seen and altered in the Data Packs screen during world creation, and by using the /datapack command.

The current load order is saved in the world's level.dat file. If you ever need to reset it, you can use the Data Packs screen during world creation or manually edit the file (not recommended unless you know what you're doing).

Handling Corrupt or Experimental Data Packs

Sometimes a data pack contains errors—maybe a malformed JSON file or a reference to something that doesn't exist. When that happens, the game shows a warning screen when you try to open the world. You'll be given two options: Safe Mode or Return to Title.

If a data pack is corrupted, broken or contains malformed entries that can't simply be ignored by the game (such as by adding a non-existent entry in a vanilla tag), an error is shown when trying to open the world that asks the player if they want to enable Safe Mode, or return to title and fix the issue.

Safe Mode disables all non-vanilla data packs, letting you get into the world and fix the problem. It's a lifesaver for servers where a broken pack could lock everyone out.

Safe Mode disables all data packs except the vanilla one, possibly allowing the world to be opened.

Data packs that use experimental features (like custom worlds or new structure sets) will also trigger a warning when the world loads. Note that worlds with experimental packs cannot be uploaded to Minecraft Realms—you'll get a server error if you try.

If a world has enabled a data pack that uses these features, opening the world in singleplayer will display a warning screen to the player.

Additionally, worlds using experimental settings cannot be played on Realms: Attempting to upload such a world to Realms results in a server error.

For more details on setting up a server with data packs, see our guide on How to Set Up a Minecraft Server Using the Official Server.jar. To learn about Realms limitations with data packs, check out Minecraft Realms: A Quick Reference for Private Server Play.