Edit NBT, level.dat and player data

NBT is the format Minecraft saves data in, and it's how level.dat and each player's .dat file are stored. You can't read one in a text editor, but a free NBT editor on your computer can open it, change a value and save it back. Do this only for the jobs a setting or command can't do, because a wrong edit can stop a world from loading.

Checked against Minecraft 26.1 and NBT Studio v1.15.3, October 2026.

Check for an easier way first

Most things people reach for an NBT editor to change have a safer route:

• Difficulty, game mode, hardcore and similar settings: the Config Editor tab edits server.properties with explanations (Minecraft server.properties explained).
• The spawn point: the setworldspawn command in the Console.
• A player's items: the Players tab. Give Items hands items over, and Clear inventory in a player's profile empties it. Players must be online for the profile actions.
• A player's location or health: Teleport and Heal in the same profile.
• Starting a player over: Reset a player's data.

Minecraft's /data command can read a player's data with get, but it can't change it: its merge, modify and remove forms fail on a player.

Pick an editor

NBT Studio opens Java NBT files such as level.dat, can undo a change, and marks a file with an asterisk until you save it. Download it from its GitHub releases and check which systems the release supports. Its newest release is from October 2022, so use it to change one value, and don't assume it understands every new field. NBTExplorer, the older tool that NBT Studio is a successor to, is older still: its last release was in 2017.

Before you edit

1. Create a backup in the Backups tab and wait for it to finish (How to create and restore backups).
2. On the Console tab, click Stop and wait for Offline, so the server can't save over the file you're editing.
3. Keep the file you download untouched, and edit a copy of it, so you can put the original back.

Edit level.dat

1. Open the File Manager and open your world folder. Its name is the World folder value in the Config Editor, world by default.
2. Find level.dat. Click Download and save it.
3. Open it in your NBT editor, change the value, and save with the same format.
4. In the File Manager, click Upload files and choose your edited level.dat. When the File already exists box appears, click Replace & overwrite.
5. Start the server from the Console tab, and join to check.

Tag names changed in Minecraft 26.1. The Player tag was replaced by singleplayer_uuid, and difficulty settings moved into a difficulty_settings tag where difficulty is now a word such as normal. Old tutorials that name tags from earlier versions may not match what your file shows, so read the tags in your own file.

Edit a player's data

Player files are named after the account's UUID, which the Players tab shows under each name. They are in playerdata on Minecraft 1.21.x and earlier, and in players/data on 26.1 and newer. The steps are the same as for level.dat: stop the server, download, edit, upload with Replace & overwrite and start.

Common tags include the inventory (Inventory), the ender chest (EnderItems), the last known position (Pos with Dimension), experience (XpLevel) and hunger (foodLevel). Edit the player only while they're offline.

If the world won't load

• The server stops on start-up and the log mentions level.dat: upload the original you kept, or restore the backup. Fix No key dimensions in MapLike (level.dat) covers one common error.
• Your change didn't stick: check the server was fully stopped when you uploaded. Repeat the steps with it stopped.
• The player's items look wrong: a value was saved with the wrong type. NBT cares about types, so a number must stay a number of the same kind. Restore the original file and try again.