What is a .fbx file?
Filmbox · 3D model · Autodesk · 2006
FBX is a rich 3D format used heavily in games and film. Beyond geometry it carries materials, textures, skeletons and animation, which makes it the go-to for moving fully rigged, animated characters between tools.
What is a .fbx file used for?
FBX bundles a complete 3D asset: meshes, materials, textures, bones, skinning and keyframe animation. That completeness is why game engines and film pipelines rely on it.
It is an Autodesk format, so support is strongest in Maya, 3ds Max, Blender and the major game engines.
FBX comes in two forms that hold the same scene: the usual binary version (which starts with 'Kaydara FBX') and an ASCII text version. It is also strongly tied to a version year, and the most common reason an FBX 'will not import' is a version mismatch between the exporting and importing tools.
The open glTF format is increasingly used for the same interchange role, especially on the web.
What opens a .fbx file?
The .fbx format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Blender
- Autodesk FBX Review
- Unity
- 3ds Max
macOS
- Blender
- FBX Review
- Unity
Linux
- Blender
Web
- Some online 3D viewers
Open a .fbx file step by step
- Confirm the file really is a .fbx. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Blender or Autodesk FBX Review.
- On Mac, use Blender or FBX Review.
- On Linux, try Blender.
- Still stuck? Convert the .fbx to OBJ, which opens more widely.
Why can't I open my .fbx file?
Almost always because no installed app understands FBX. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .fbx at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .fbx file
You can convert a .fbx file to OBJ, GLTF, STL using a conversion tool or the export menu of an app that opens it.
What is the .fbx file signature (magic bytes)?
A .fbx file starts with the hex bytes 4B 61 79 64 61 72 61 20 46 42 58, which read as Kaydara FBX in ASCII. Programs identify FBX by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for FBX. For a full breakdown, see the FBX (binary) file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 4B 61 79 64 61 72 61 20 46 42 58 | 0 | Kaydara FBX | 'Kaydara FBX' (binary FBX) |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .fbx file?
FBX is a rich 3D format used heavily in games and film. Beyond geometry it carries materials, textures, skeletons and animation, which makes it the go-to for moving fully rigged, animated characters between tools.
How do I open an FBX file for free?
Blender opens and edits FBX for free. Autodesk's free FBX Review app previews them with animation.
Why won't my FBX import correctly?
Usually a version mismatch: FBX is versioned by year, and older software may reject a newer file. Re-export it to an earlier FBX version (2013 or 2014 are safe choices). Missing textures are a separate issue, FBX often references image files that must travel alongside it.
Related formats
Sources
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