# USDZ to STL converter

> Convert USDZ, USD, USDA and USDC files to STL or 3MF in your browser, scaled from metres to millimetres. Great for iPhone object scans. Free, no upload.

Source: https://freestlviewer.com/usdz-to-stl/  
Updated: October 22, 2026

Convert USDZ and USD files — including iPhone object scans — into a printable STL in millimetres. Converted in your browser, never uploaded. The tool is interactive: open https://freestlviewer.com/usdz-to-stl/ and drop a file onto the page.

## From AR model to printed part

USDZ is Apple's format for AR: what Object Capture and many iPhone scanning
apps produce, and what product pages offer for "View in AR". Printing one
means converting it to STL or 3MF at the right size.

## Scale

USD scenes declare their scale with `metersPerUnit`; Mes3D applies it, so the
geometry arrives in metres. Slicers assume millimetres, so the converter
preselects **metres** and multiplies by 1,000. A 15 cm scan stays 150 mm.

If the summary shows an implausible size, the scan itself was not at real
scale — fix it in your slicer after converting, or pick another source unit.

## Scans need a check before printing

- **Holes.** Object scans usually have an open base where the object stood.
  The summary's watertightness line will say so. Most slicers close small
  holes; a large opening needs a mesh tool.
- **Density.** Scans can have far more triangles than any printer resolves,
  which makes slicing slow. See
  [STL file size and triangle count](https://freestlviewer.com/blog/triangle-count-and-file-size/).
- **Thin parts.** Fine details that look good in AR may be thinner than a
  nozzle can print.

## What is kept

| From the USDZ | In the STL | In a 3MF |
| --- | --- | --- |
| Geometry, at its scene position | Yes | Yes |
| Solid material colours | No | Yes |
| Photographic textures | No | No |
| Animation, physics, anchors | No | No |

## On a phone

USDZ conversion works in Safari on iPhone and iPad, and the result can be
saved to Files. The Mes3D app opens USDZ, STL and other formats and adds AR,
measuring and STL/OBJ/3MF export on iPhone, iPad, Mac and Android.

## Frequently asked questions

### How do I convert a USDZ to STL?

Drop the .usdz onto this page. Metres is preselected, since USD scenes come in metres; keep STL selected and click Convert and download. The STL is written in millimetres at real size.

### Can I 3D print an iPhone object scan?

Usually, yes. Convert the USDZ to STL, then check the summary: scans are often open at the bottom and very dense. Slicers can close small holes; larger gaps need a mesh tool. Scale may also need adjusting if the scan was not captured at real size.

### Are textures kept?

No. STL is geometry only. 3MF output keeps solid colours, but the photographic textures of scans are not carried over.

### Does it work for Reality Composer files?

Yes, USDZ packages from Reality Composer, Object Capture and other Apple tools open as long as the geometry is inside the package.