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OBJ to FBX: How to Convert (and What Gets Lost)
Going from OBJ to FBX is a lossy step in some directions and a no-op in others. Here is what each format actually carries, what survives the conversion, and the methods worth using in 2026.
What is OBJ?
OBJ is a plain-text geometry format that has barely changed since the early 1990s. It stores vertices, faces, vertex normals, and texture coordinates, with materials kept in an accompanying .mtl file. It is human-readable, easy to parse, and supported essentially everywhere — which is why it remains the most common interchange format between modeling tools.
- Plain-text format, line-based and trivially diffable
- Materials live in a separate .mtl file alongside the .obj
- Supports vertex colors, UVs, normals, and named groups
- No animation, no rigging, no scene hierarchy
What is FBX?
FBX is the workhorse interchange format of the game and animation industries. Owned by Autodesk since 2006, its closed binary specification stores meshes, materials, textures, skeletons, animations, lights, cameras, and full scene hierarchies. Game engines (Unity, Unreal, Godot) and DCC tools (Maya, 3ds Max, Blender) all read and write FBX, even though no perfect open-source spec exists.
- Industry-standard for rigged characters and animations
- Closed binary format reverse-engineered by the FBX SDK and Blender
- Full scene graph: lights, cameras, hierarchy, constraints
- Not natively supported in browsers — convert to GLB for the web
How to convert OBJ to FBX
OBJ and FBX have overlapping capabilities, and most converters get the geometry right. The differences show up around materials, units, axis orientation, and what each tool downstream expects.
- Blender (free, all platforms). Open Blender, File → Import → OBJ (.obj), then File → Export → FBX (.fbx). Blender has native importers and exporters for every format on this page except STEP (which needs the optional CAD Sketcher addon or a separate STEP-to-mesh pass). The export dialog exposes the settings that matter: scale, axis orientation, and whether to embed materials and animations.
What gets preserved, what gets lost
Geometry-wise, OBJ and FBX carry the same essential data, so this conversion is reasonably lossless.
Common use cases
- Importing into Unity or Unreal Engine for a game project
- Sending to an animator working in Maya or 3ds Max
Questions
Is OBJ to FBX conversion lossy?
For the geometry, no — vertices and faces map cleanly. There may be small precision differences depending on the tool, but nothing visible. Color, texture, and animation data depend on the specific source and destination — see the preservation notes above.
Can I do this conversion online for free?
Yes — for files under ~50MB, browser-based converters handle this pair quickly. For larger files or anything proprietary, use Blender locally so the file does not leave your machine. Both options are free.
Can Automatic3D output FBX directly?
Automatic3D's primary output is STL, optimized for 3D printing. For FBX-specific workflows, convert from the STL using one of the methods above.