USD to glTF Converter
FileFlip converts USD to glTF 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 USD file to glTF?#
- Drop your USD 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 glTF 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 glTF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting USD to glTF lose quality?#
Not in the sense of pixels or samples. Converting USD to glTF rebuilds the file in glTF's own model rather than re-encoding it, so everything glTF 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 USD files online?#
Yes, because nothing is uploaded. FileFlip converts USD 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 USD to glTF actually does to the file#
Converting USD to glTF 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: USD → glTF |
| 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, or a ZIP when the source carries separate materials or buffers |
| 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. |
Worth knowing before you start:
- the result is a single file when the model has no external materials or buffers, and a ZIP when it does
What is a USD file?#
A USD file holds a 3D scene written in Pixar's Universal Scene Description language, saved under the generic .usd extension, which can contain either the ASCII text encoding or the binary Crate encoding without the extension telling you which.
Use the plain .usd extension when a tool needs to write out a scene without committing to a specific ASCII or binary encoding.
Convert to USDA when a layer needs to be read or diffed as text, or to USDZ when the file needs to open directly in AR Quick Look.
What is a glTF file?#
A glTF file is a JSON scene description, developed by the Khronos Group and first released in 2015, that lists a model's meshes, PBR materials, animations and scene hierarchy while its binary geometry and textures sit alongside it in separate buffer and image files.
Use glTF's JSON form when a pipeline needs to inspect or hand-edit the scene structure directly, since it's plain, indexed JSON.
Convert glTF to GLB when the model needs to travel or load as a single file instead of a folder of JSON, buffers and textures.
USD to glTF questions people ask#
What is the difference between USD, USDA, USDC and USDZ?
USD is Pixar's Universal Scene Description format, and USDA, USDC and USDZ are its three concrete file forms: USDA is the ASCII text encoding, USDC is the binary Crate encoding, and USDZ is a zero-compression ZIP package of USD layers plus their textures and other assets. A plain .usd file can be either ASCII or Crate underneath; USDA and USDC exist so the encoding is explicit in the extension.
Is a USD file text or binary?
A .usd file can be either, since USD's generic extension doesn't fix the encoding the way .usda or .usdc do. Opening the file in a text editor is the fastest way to tell: readable text starting with #usda means ASCII, anything else means it's the binary Crate form.
Can I open a USD file in Blender?
Yes, Blender has built-in USD import and export, handling .usd, .usda and .usdc files including their materials and, in recent versions, animation.
Do I need Pixar's own software to use USD files?
No. Pixar's usdview and command-line tools are the reference implementation, but USD support is built into Blender, Autodesk Maya, and NVIDIA Omniverse, among others, so opening or editing a USD file doesn't require Pixar's tools specifically.