ZGL to USDZ Converter
FileFlip converts ZGL to USDZ entirely inside your browser, using Assimp compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a ZGL file to USDZ?#
- Drop your ZGL file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to USDZ and the conversion starts on its own. FileFlip downloads 11.2 MB of WebAssembly the first time and nothing after that, then runs Assimp on your own machine.
- Save the USDZ file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting ZGL to USDZ lose quality?#
Not in the sense of pixels or samples. Converting ZGL to USDZ rebuilds the file in USDZ's own model rather than re-encoding it, so everything USDZ can represent comes through exactly and anything it cannot has to be dropped. Expect the geometry to be exact, and anything the target has no place for, such as a rig, to be left behind.
Is it safe to convert ZGL files online?#
Yes, because nothing is uploaded. FileFlip converts ZGL files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What ZGL to USDZ actually does to the file#
Converting ZGL to USDZ runs on Assimp, downloads 11.2 MB of WebAssembly the first time and nothing after that, rebuilds the file in the target's own model.
| Engine | Assimp |
|---|---|
| Conversion path | One step: ZGL → USDZ |
| Downloaded to your browser | 11.2 MB, once, then cached by your browser |
| Quality | Rebuilt in the target's model |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Materials | Sometimes | Survives for some files and not others. |
| Textures | Sometimes | Survives for some files and not others. |
| Skeleton and animation | Sometimes | Survives for some files and not others. |
What is a ZGL file?#
A ZGL file is an XGL 3D scene, meshes, materials, lighting and a transform hierarchy under a root WORLD element, run through gzip compression, which is how the verbose XGL XML is usually distributed.
Use ZGL wherever an XGL scene is being distributed or stored and file size matters, since it's the same data compressed.
Convert ZGL to glTF or OBJ for anything outside the original CAD visualisation tooling, since ZGL support is rare elsewhere.
What is a USDZ file?#
A USDZ file is a zero-compression ZIP archive holding one or more USD layers together with their textures, audio and other referenced assets, packaged as the single file Apple's AR Quick Look expects.
Use USDZ when a model needs to open in AR Quick Look on an iPhone or iPad, or travel as one self-contained file with its textures attached.
Convert away from USDZ when the model is headed into a DCC tool or pipeline that expects an unpacked USD layer rather than a zip package.
ZGL to USDZ questions people ask#
What is a ZGL file?
A ZGL file is a gzip-compressed XGL scene, the same XML mesh, material, lighting and transform data as an XGL file, just shrunk down. A reader decompresses it first and then parses it exactly like XGL.
How do I open a ZGL file?
A ZGL file needs a tool that specifically supports the XGL/ZGL format, since it isn't a general-purpose gzip archive despite using the same compression. Decompressing it manually with a gzip utility recovers the underlying XGL XML, which can then be inspected as text.
Is ZGL a different format from XGL?
No. A ZGL file holds the exact same XGL scene structure, just compressed. Nothing about the meshes, materials or hierarchy changes between the two.
What opens a USDZ file?
On a Mac or iPhone, USDZ opens straight in Quick Look from the Finder, Safari, Messages or Mail with no separate app needed. Blender and Adobe Aero also read USDZ on any platform if you need to edit rather than just view it.