NBT Changer

The NBT Changer modifies the world files directly by changing specific values.

Fields

The following values can be changed:

Field	Type	Description
LightPopulated	byte	Whether the light levels for the chunk have been calculated. If this is set to 0, converting a world from 1.12.x to 1.13 will omit that chunk. Allowed values are 0 and 1
DataVersion	int	Allows to change the DataVersion of the chunks. Should be used with extreme care.
InhabitedTime	long	This field stores the amount of game-ticks players have spent in a chunk. Impacts the local difficulty.
Timestamp	int	The time in epoch seconds when the chunk was last saved.
LastUpdate	long	The time in ticks since world creation when the chunk was last saved.
Status	String	The status of the chunk generation. Only recognized by Minecraft 1.13+ (DataVersion 1444+)
Biome	String/int	A biome name or ID. This sets all biomes of this chunk to a single biome. For a reference of biome names and IDs, have a look at the Wiki. Custom biomes can be specified by using single quotes (') around a biome ID.
ReplaceBlocks	String	A comma separated list of block replacements in the format `=<block-name\
DeleteEntities	boolean	If set to 1 or true, all entities in that chunk will be deleted.
DeleteSections	boolean	One or a range of section indices. A range has the format <from>:<to>, inclusive. Omitting <from> sets the lowest possible value, omitting <to> sets the highest possible value. : or true means all sections. Multiple ranges or single indices can be defined by separating them with a comma.
FixStatus	boolean	Will look for chunks that have terrain data, but their Status is set to empty and sets their Status field to full. Having terrain data but the Status set to empty can sometimes happen when upgrading the world through a long upgrade path, e.g. from Minecraft 1.12 directly to 1.16.
DeleteStructureReference	String	Deletes the specified structure references from a chunk. Multiple references can be chained with a , and non-vanilla references can be specified in single quotes (').
PreventRetrogen	boolean	Can be used after upgrading a world to 1.18 to prevent Minecraft from generating caves below Y=0.
ForceBlend	boolean	Can be used to force chunks generated in 1.18 to blend with other chunks generated in 1.18.

Once the field is highlighted in green, the value is considered valid and will be changed. A gray field, no matter its content, will be ignored.

Field string

A string representation of the to-be-changed fields is printed in a text field below the editor. When entering a valid string into this field directly, press Enter to parse it into the editor.

For more information about the fields have a look at the chunk format description on Minecraft Wiki.

Options

Change

When this option is selected, the fields will only be changed if they already exist in the chunk.

Force

When this option is selected, the fields will be forcefully added to the chunk. This only works if the chunk already exists and it doesn't work for all fields: Exemptions are the ReplaceBlocks, DeleteEntities, DeleteSections and FixStatus fields.

Apply to selection only

When this option is selected, only the fields in the current selection will be changed or set. If this is not set, it will change / set the fields in all existing chunks.