Bedrock NBT Editor

Online NBT editor for Minecraft Bedrock Edition level.dat files. Built for the PocketMine-MP community.

The Problem

When you duplicate a Bedrock world by copying its folder, the internal LevelName tag inside level.dat doesn't change — it still references the original world name. This causes confusing bugs in PocketMine-MP and MCPE/MCBE. This tool lets you fix that (and edit any other NBT tag) directly in your browser.

Features

• Full Bedrock NBT support — all 13 tag types including TAG_Long (BigInt)
• Parses Bedrock level.dat format (8-byte LE header + LE NBT payload)
• Tree view editor with collapsible compound/list nodes
• Inline value editing — click any value to change it
• Add and remove tags
• Download modified file with correct header
• Drag & drop or file picker upload
• Mobile-first, touch-friendly UI (44px+ tap targets)
• Dark theme, no frameworks, zero dependencies
• Works 100% client-side — your files never leave your browser

How to Use

1. Open the editor
2. Drag & drop your level.dat file (or click to browse)
3. Expand the tree to find the tag you want to edit (e.g. LevelName)
4. Click the value to edit it inline
5. Click Save & Download to get the modified file

Technical Details

• Bedrock level.dat has an 8-byte header: 4 bytes LE version integer + 4 bytes LE payload length
• All NBT data is little-endian (unlike Java Edition which is big-endian)
• TAG_Long values are handled with JavaScript BigInt for full 64-bit precision
• The editor recalculates the payload length on save

Supported Tag Types

ID	Tag Type	Description
0	TAG_End	Marks end of compound
1	TAG_Byte	Signed 8-bit integer
2	TAG_Short	Signed 16-bit LE integer
3	TAG_Int	Signed 32-bit LE integer
4	TAG_Long	Signed 64-bit LE integer (BigInt)
5	TAG_Float	32-bit LE IEEE 754 float
6	TAG_Double	64-bit LE IEEE 754 double
7	TAG_Byte_Array	Length-prefixed byte array
8	TAG_String	Length-prefixed UTF-8 string
9	TAG_List	Typed list of tags
10	TAG_Compound	Named collection of tags
11	TAG_Int_Array	Length-prefixed int array
12	TAG_Long_Array	Length-prefixed long array

Keywords

PocketMine-MP, PMMP, PocketMine, Bedrock Edition, MCPE, MCBE, level.dat, NBT editor, world editor, level name editor, Minecraft Bedrock tools, NBT viewer, online NBT editor

License

MIT