Convert GLB to USDZ
USDZ is what an iPhone or iPad opens when you tap a 3D model: it stands up in the room in front of you, at its real size. This turns a GLB into one on your own computer, with its textures intact.
Drag a 3D file here, or.
This page is set up for GLB files. Other formats we can read work here too.
The file is read on your own computer. It is never uploaded.
Your file is read by your own browser and never sent to a server. There is no upload, no account and no copy of your model anywhere but on your computer.
The two formats line up almost exactly
GLB and USDZ describe a surface the same way — triangles, texture coordinates, and a physically based material with a base colour, a roughness and a metalness. That is why this is the one conversion into USDZ that loses almost nothing.
The base colour texture, the normal map, roughness, metalness and occlusion all come across, and the images are packed into the USDZ next to the model, exactly as they were packed into the GLB.
The size is set for you, and that is deliberate
A USDZ file has no way to say what unit its numbers are in. Every one of them is read as metres, and Quick Look believes it without asking. Get that wrong and a 60 mm bracket is placed in the room sixty metres tall, which usually looks like nothing at all appearing.
GLB is already in metres, so this pair needs no adjustment — but the file is written in metres regardless of what the unit boxes say, because it has to be. The measurements shown beside the 3D view switch to metres to match, so what you read is what is in the file.
How to actually open it
Send the .usdz to yourself and open it on an iPhone or iPad — in Messages, in Mail, or from Files. It opens in Quick Look, and the AR button puts it in the room. On a Mac, double-clicking previews it in the same viewer.
On Android and on Windows, USDZ is not the format to use; send a GLB instead. Scene Viewer and the Windows 3D viewer both read GLB directly.
What is actually inside a USDZ file
A USDZ is a ZIP archive, but an unusual one: nothing inside it may be compressed, and every file has to start at a 64-byte boundary. Both rules exist so that a phone can read the model straight out of the archive without unpacking it first, which is what makes Quick Look open instantly on a file that might be fifty megabytes.
Inside is a USD scene describing the geometry and materials, plus the texture images as ordinary PNG or JPEG files. The USD written here is the readable text form, `usda`, rather than the binary `usdc` that Apple’s own tools produce. Both are valid and Quick Look reads both.
That choice is also why this conversion only runs one way. Writing a USD scene means emitting text and zipping it, which is straightforward. Reading one back means handling the binary crate format, which has no implementation outside Pixar’s library — so we write USDZ and cannot read it, and say so rather than offering a button that fails.
What survives, and what does not
Kept in the USDZ file
- The exact shape of every mesh, in the place the scene put it
- The base colour texture and the other material maps
- Texture coordinates, so the pictures land where they belong
- The real size, written in metres as USDZ requires
Lost on the way
- Animation, skinning, cameras and lights
- glTF extensions that have no USD equivalent
How to convert GLB to USDZ
Drop the .glb file in
Textures and materials are already inside it, so nothing else is needed. This is the cleanest source format for USDZ.
Check the size in metres
The measurements beside the 3D view switch to metres, because that is the only unit a USDZ can be read in. A chair should say about 0.9; a phone case about 0.15.
Frame the model the right way up
Quick Look stands the model on the floor of the room. A model lying on its back in the 3D view will lie on its back on the table.
Download the .usdz
One archive with the geometry, the materials and every texture image inside it.
Send it to an iPhone or iPad
Message it or mail it to yourself and tap it. It opens in Quick Look, and the AR button puts it in the room at the size the file says.
GLB and USDZ compared
| Property | GLB.glb | USDZ.usdz |
|---|---|---|
| File contents | One binary file: a small header, the same JSON as glTF, then all the buffers and images. | An uncompressed ZIP holding a USD scene and its textures, aligned so it can be read in place. |
| Geometry | Triangles, with skinning weights and animation channels alongside them. | Triangles, plus subdivision surfaces that most readers ignore. |
| Units | Metres, fixed by the specification. | Centimetres by default, with a metersPerUnit value in the file that can change it. |
| Colour and texture | Full physically based materials, with the texture images packed inside the file. | Physically based materials through UsdPreviewSurface, with textures inside the archive. |
| Separate objects | A scene graph of named nodes, each with its own position and rotation. | A full USD scene graph of named primitives. |
| Published by | The Khronos Group, 2015, as the single-file packaging of glTF. | Pixar and Apple, 2018, for augmented reality on iOS. |
| Written by | Blender, Sketchfab, Substance Painter, and every tool that ships models to the web. | Reality Composer, Blender through an add-on, and Apple’s own conversion tools. |
Questions
- Can you convert USDZ back to GLB?
- No, and we would rather say so than offer a button that fails. A USDZ is an archive holding a USD scene, and the USD inside is almost always the binary usdc form, which has no reader outside Pixar’s own library. Apple’s Reality Converter on a Mac, or Blender, will open one.
- It opens on my Mac but the AR button does nothing.
- AR needs an iPhone or iPad. On a Mac, Quick Look shows the model in a window but there is no camera view to place it in.
- The model is the wrong size in the room.
- A USDZ is always read as metres. If your GLB was built at a scale where one unit meant a millimetre, the model will be a thousand times too big. Fix the scale in the source model, or set the first unit box to what the GLB really used.
- Is my file uploaded anywhere?
- No. The conversion runs inside your browser on your own computer. Nothing is sent to a server.
- Is the USD inside binary or text?
- Text — the readable `usda` form. Apple’s own tools usually write the binary `usdc`, and Quick Look reads either. The text form is why we can write these files at all in a browser.