Online NBT Editor for Minecraft Saves
Open, inspect and edit NBT files — level.dat, playerdata, structure .nbt files and more — right in your browser. No install, no upload: every byte is processed locally on your machine.
100% client-side · Free · Works with gzip, zlib and uncompressed NBT
What can you do with it?
Inspect level.dat
See world name, seed, spawn point, game rules, DataVersion and everything else a world file stores — as a readable tree.
Edit player data
Adjust positions, inventory entries, health, game mode flags and other values stored in playerdata .dat files.
Export losslessly
Download the edited file in its original compression format — gzip, zlib or uncompressed — or pick a different one.
How it works
- Open — drop a .dat or .nbt file onto the editor. The compression format (gzip, zlib or raw) is detected automatically.
- Edit — browse the tag tree, change values, rename keys, add or delete tags. Numbers, strings, lists, compounds and byte/int/long arrays are all editable.
- Export — download the edited file and put it back into your save folder. Round-trip is verified by automated tests.
Why a browser-based NBT file viewer?
Nothing to install
No launcher, no runtime, no admin rights. If you have a browser, you can open an NBT file — on Windows, macOS, Linux or a Chromebook.
Your saves stay yours
The parser runs in JavaScript in your tab. There is no backend and no upload code — check the network tab, it stays silent.
Built on the public spec
NBT (Named Binary Tag) is a documented, community-standard binary format. Read our complete format explanation to understand every byte.
Frequently asked questions
Is it safe to edit my Minecraft world files?
The editing itself is risk-free for your privacy because files never leave your browser. Still, save files are important data: always keep a backup copy of a world before you put an edited file back. A corrupted level.dat can make a world unopenable.
Which files can I open?
Any Java-edition NBT file: level.dat, level.dat_old, playerdata/<uuid>.dat, structures/*.nbt, servers.dat and similar. Region files (.mca) store NBT chunks internally but use an extra container layer that this tool does not open.
What are gzip, zlib and uncompressed NBT?
The same NBT payload can be wrapped in different containers. Vanilla writes level.dat as gzip; other tools and formats use zlib or store raw NBT. The editor detects the format automatically and exports in the same one by default.
Do I need to know the NBT format to use the editor?
No — the tree view shows names and values like a file explorer. If you want to understand what the type names (TAG_Compound, TAG_Long, and so on) actually mean byte-wise, the NBT format guide explains the whole binary layout.
Does it work offline?
After the page has loaded, all parsing and editing happens in your browser. Once the tab is open you can even disconnect from the network and keep editing.
Common uses
- Check a world's seed and DataVersion before migrating it between game versions.
- Fix a spawn point that traps players in the void after a bad portal link.
- Compare game rules between two worlds without launching the game.
- Inspect structure block exports (
.nbt) before sharing them. - Learn binary file formats hands-on with a real, safe example file.