USD File Format (.usd)
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.
USD at a glance#
| Full name | Universal Scene Description |
|---|---|
| File extension | .usd |
| Category | 3D Models |
| Developer | Pixar Animation Studios |
| First released | 2016 |
| Compression | Lossless |
| FileFlip support | FileFlip reads this format but does not write it |
What a .usd file can hold#
These are the things a USD file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Animation | Yes |
|---|---|
| Layers | Yes |
| Embedded metadata | Yes |
| Textures and materials | Yes |
| Skeletons and animation | Yes |
| Schema or validation | Yes |
Strengths and limitations of USD#
What USD does well
- Composes many layers into one scene, each contributor's file staying separate and overridable rather than merged destructively
- Same data model whether the file underneath is text or binary, so tools round-trip between the two without loss
- Backed by Pixar and now the Alliance for OpenUSD, so support keeps expanding into games, robotics and product design beyond film
Where USD falls short
- The plain .usd extension doesn't say whether the file is ASCII or Crate binary underneath, so some tools guess wrong
- Full composition semantics, layers, variants, payloads and references, are complex enough that many viewers only implement a subset
- Outside major DCC tools and engines, support is still thin compared to something like glTF
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.
How to open a .usd file#
A .usd file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts USD into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | Blender, Autodesk Maya, NVIDIA Omniverse |
| macOS | usdview, Blender, Autodesk Maya, NVIDIA Omniverse |
| Linux | usdview, Blender, NVIDIA Omniverse |
| Web | FileFlip |
USD 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.
Converting USD files#
Convert USD to another format
FileFlip does not write .usd files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.