Convert OBJ to USDZ
Free OBJ to USDZ converter that runs in your browser. See real dimensions before you download.
Why convert OBJ to USDZ?
OBJ to USDZ is a way to take a classic modelling export, a scan or a downloaded asset and open it in AR on an iPhone or iPad. USDZ is the format Apple's AR Quick Look reads from Safari, Messages, Mail and Files. The OBJ's geometry and UVs are kept, and MTL colours and textures are packed into the USDZ. The main thing to watch is scale: OBJ stores no unit, while USDZ is in metres, so a model built in millimetres or centimetres will look absurdly large in your living room unless it is scaled. MeshShift shows the real dimensions before converting so you can pick the right factor. Y-up OBJ files from Blender already match USDZ's orientation.
How to convert OBJ to USDZ
- Drop your OBJ file (with its textures, if separate) onto the converter — it opens in your browser, nothing is uploaded.
- Check the preview and the dimensions in mm; fix units or the up axis in “Units & orientation” if the size or orientation looks wrong.
- Choose USDZ as the output and click Convert. Several files download as one ZIP.
What carries over from OBJ to USDZ
| OBJ | USDZ | Result | |
|---|---|---|---|
| Colour / materials | Yes | Yes | Kept |
| Textures | Yes | Yes | Kept |
| Units stored in file | No | Yes | Written as mm → metres |
| Separate parts | Yes | Yes | Kept |
| Usual up axis | Y | Y | Unchanged |
What changes
- Scale is chosen during conversion because OBJ has no unit; USDZ is in metres.
- MTL colours and textures are packed into the USDZ.
- Older Phong material properties are approximated by USD's preview surface.
- Quads are triangulated; named objects become separate meshes.
Tips
- Upload the OBJ with its MTL and texture images so the USDZ looks right.
- If the model appears huge in AR, apply a 0.001 scale for millimetre models or 0.01 for centimetres.
- Open the USDZ on an actual iPhone to verify size and colours.
- Keep textures reasonably small for quick AR loading.
About OBJ files
OBJ comes from Wavefront Technologies' Advanced Visualizer software in the 1980s, and it has outlived the product. A file is plain text: lines starting with v define vertices, vt texture coordinates, vn normals, and f faces that reference those lists by index. Faces may be triangles, quads or larger polygons, and the g and o keywords group faces into named objects. Appearance is not in the OBJ at all; a line called mtllib points to a separate .mtl file that lists materials with diffuse colours and texture image names. The format is verbose, has no official unit and no scene hierarchy or animation, but it is trivial to read and write. That is why scanners, photogrammetry tools, sculpting programs and game pipelines still use it to move static meshes around.
About USDZ files
USD, Universal Scene Description, was created at Pixar for film production and released as open source in 2016. USDZ was introduced by Apple and Pixar in 2018 as a single-file, uncompressed and unencrypted zip archive that packs a USD scene with its textures so it can be delivered and displayed without extra files. Apple built USDZ into iOS, iPadOS, macOS and visionOS: tapping a .usdz link in Safari or Messages opens AR Quick Look, where the object can be placed in the room at real-world scale. The file format is aligned with USD's metersPerUnit and upAxis metadata, and uses physically based UsdPreviewSurface materials. Retailers use it for product previews, and the format also appears in Reality Composer, Xcode and Blender's USD exporter. It is a viewing and AR format, so it plays no role in slicing.
3D printing notes
Slicers import OBJ geometry and ignore the material file, so what you print is the shape only. Bambu Studio and OrcaSlicer can use the colours from an OBJ for multi-colour assignment on import, but results depend on the exporter. The main trap is orientation and scale. Blender usually writes Y-up files while slicers expect Z-up, so a model may arrive lying on its back, and a model sculpted at one unit per metre can be tiny. MeshShift has an Up-axis fix that rotates Y-up models so they stand upright, shows real dimensions before conversion, and can convert OBJ to STL or 3MF in the browser.
Frequently asked questions
Why is my OBJ giant in AR?
OBJ has no unit, and USDZ uses metres. A model drawn in millimetres reads as 1000 times too large unless scaled. Use the dimension labels in the converter to set the correct scale.
Are textures included in the USDZ?
Yes, if you upload the texture images with the OBJ and MTL. They are packed into the USDZ, which then works as a single file.
Is this OBJ to USDZ converter free and private?
Yes. The conversion runs in your browser with JavaScript and WebAssembly, so your OBJ file is never uploaded to a server. There is no sign-up, no watermark and no daily limit; very large files are limited only by your device's memory.