Unpacks a GLB into a .gltf JSON document. Nothing is recomputed; the binary chunk is embedded as a data URI so the result is still one file, and the scene graph becomes text you can read and edit.
What you get, and what it costs
.gltf. The JSON is pretty-printed, so you can open it and see the nodes, meshes, materials and animations, and edit them by hand — change a material's base colour, rename a node, remove an animation.
The cost is size. Base64 is four characters per three bytes, so the embedded buffer is a third larger than the raw binary, and the pretty-printing adds more. A 5 MB GLB becomes roughly a 7 MB .gltf. For inspection that does not matter; for shipping, keep the GLB.
It round-trips exactly
What the separate files are for
Other names for this
Also searched as “unpack glb”, “glb to json”.
Questions
- Do I get a separate .bin file?
- No. The binary data is embedded as a data URI so the result stays a single file.
- Why is the .gltf bigger than the .glb?
- Base64 encoding adds about a third, and pretty-printing the JSON adds more. That is the price of a text format.
- Can I edit it and convert back?
- Yes. The round trip is exact, so an edited .gltf repacks into a GLB with the geometry untouched.
- Is my model uploaded?
- No. The parsing and rewriting happen in this tab. Models are frequently confidential — an unreleased product, a client’s part, a scan of something proprietary — and none of it is transmitted. Turn your Wi-Fi off and the tool keeps working.