STL to USDZ Converter

See a print in your room before you print it: STL to USDZ for AR Quick Look at true size.

  • Files stay on your device
  • Free, no sign-up
  • Units and up axis handled
  • Batch and .zip

Drop an STL file to convert

One file, many, or a .zip

In: STL · STEP · IGES · OBJ · 3MF · GLB · glTF · PLY · FBX · DAE · 3DS · AMF · VRML · ZIP

Converted on your device. Nothing is uploaded.

    How to convert STL to USDZ

    1. Drop your STL files

      Drop one or more .stl files, binary or ASCII, or a .zip of them.

    2. Check the preview

      The model appears at the size and orientation it will have. Fix the file units, up axis or size under Size, units and orientation if needed.

    3. Choose USDZ options

      Written in metres, Y up, sitting on the floor and centered, which is what AR Quick Look expects.

    4. Convert and download

      One file downloads straight away. A batch gives a download per file and one .zip of all of them.

    What carries over from STL to USDZ

    Worked out from what each format can store and what this converter writes. Nothing is changed silently: the preview shows the size and orientation before you download.

    Geometry Every triangle is kept at full precision.
    Color STL has no color to carry. The USDZ comes out uncolored.
    Units Converted from millimetres to metres, so it keeps its real size. A 50 mm part is written as 0.05.
    Orientation Turned from Z up to Y up, so it stands upright in web viewers and AR.
    Objects Each part stays a separate object or mesh.

    STL to USDZ: what actually happens

    The converter turns the STL's millimetres into USDZ metres, stands it on the floor and gives it a neutral material. Open the .usdz on an iPhone or iPad, tap AR, and the part appears at the size it will print.

    It is a quick way to check scale, a display stand's footprint or how a figure looks on a shelf before committing filament.

    STL at a glance

    Stereolithography (Standard Triangle Language) · .stl

    Stores
    Loose triangles: three corners and a normal each, binary or ASCII
    Color
    None in the standard
    Units
    None written; slicers assume millimetres
    Up axis
    Z, the slicer convention
    File size
    50 bytes per triangle in binary, about 5 times that as ASCII
    Opens in
    Every slicer, CAD tool and 3D app

    Created by 3D Systems in 1987 for the first stereolithography printers, STL is still the format every slicer and print service accepts. It describes a surface as a list of independent triangles, with no shared vertices, units, colors or scene structure.

    Open STL files in the viewer

    USDZ at a glance

    Universal Scene Description, zipped · .usdz

    Stores
    A Pixar USD scene and its textures in an uncompressed zip
    Color
    PBR materials and textures
    Units
    Metres in this export
    Up axis
    Y
    Use
    AR Quick Look on iPhone, iPad, Mac and Vision Pro
    Opens in
    Safari and Files on Apple devices, Reality Composer, Blender, Omniverse

    USDZ packages Pixar's Universal Scene Description for Apple's AR Quick Look: tap a .usdz on an iPhone and the model appears in your room at real size.

    Tips for STL to USDZ

    Scale check

    Set the exact size first; AR is true to scale.

    Share it

    Send the .usdz in Messages; it previews in AR on the other end.

    Android

    Use STL to GLB for Android Scene Viewer.

    STL to USDZ FAQ

    Is the AR model true to size?
    Yes. Millimetres are converted to metres, which AR Quick Look shows at real scale.

    Does it keep color?
    STL has none; the model is a neutral grey.

    Do I need an app?
    No. iPhone and iPad open USDZ with the built-in Quick Look.

    Is the converter free? Are there limits?
    Free, with no sign-up, watermark or file count limit. Batches and files of a few hundred MB work on most laptops; the only limit is your device's memory.

    Are my files uploaded?
    No. Files are read and written by JavaScript and WebAssembly in your browser and never sent to PrintPal. The STEP and IGES reader is the only extra download, once, from a public CDN.