FBX to OBJ

Converting FBX to OBJ step by step

1. Drop your .fbx onto the converter. Textures don't matter for an OBJ, so there's no need to add them, though they make the preview easier to judge.

2. Look at the preview. If the model is rigged, it shows the rest pose stored in the file, which for a rigged character is usually a T-pose, and that is the pose the OBJ gets.

3. Click convert and download the .obj. FBX and OBJ both use Y as up, so the model keeps its orientation and no axis fix is offered.

Open the result in your target app. Because OBJ is text, you can also open it in any editor to check it really contains geometry: lines starting with v are vertices, f are faces.

When FBX to OBJ makes sense

OBJ is the plain-text lowest common denominator of 3D. Almost every modeler, sculpting app, CAD viewer and 3D printing tool can open it, including old ones that never got an FBX importer. Converting FBX to OBJ is the way to get the shape out of an FBX when the receiving program doesn't read FBX, or when you only want the mesh and none of the rig.

Typical cases: pulling a character out of a game asset to sculpt on it in ZBrush or Blender, taking a posed figure into a tool that only accepts static meshes, or handing a model to someone whose software predates FBX 7. The converter does this in the browser with no upload.

OBJ keeps the shape, not the look

Be clear about this before converting: the OBJ written here is geometry only. There is no .mtl file and no textures in the output. If you need materials and textures to survive, convert to GLB instead.

Vertices and faces

Kept, in the same coordinates as the FBX.

Normals

Kept, so smooth and hard edges look the same.

UV coordinates

Kept. You can reapply the original textures by hand in the target app because the UV layout is intact.

Meshes

Each FBX mesh is written as its own group in the OBJ, so parts stay separable.

Materials and textures

Dropped. No .mtl is written, and the model opens gray.

Skeleton and animation

Dropped. OBJ has no concept of bones. A skinned mesh is written in the rest pose stored in the file, which for a rigged character is usually a T-pose.

Morph targets

Dropped. Only the base shape is written.

Things that trip people up

Most complaints after an FBX to OBJ conversion are about what OBJ can't hold rather than about the conversion going wrong.

Need textures and animation kept? Use FBX to GLB.

OBJ opens gray

Expected. No .mtl or textures are written. Reassign the original image files in your 3D app; the UVs are there to receive them.

Character is in a T-pose, not the pose I wanted

The converter writes the rest pose stored in the file, which for a rigged character is usually a T-pose. If you need a particular frame of an animation, bake that pose in your DCC tool and export the FBX again with the mesh frozen there.

FBX version not supported

FBX 6.x and older can't be read. Convert it with Autodesk's FBX Converter, or re-export it as FBX 7.x from the app that made it. Blender can't help here: its importer reads FBX 7.1 and newer only.

Model is enormous or tiny

No rescaling happens. A centimeter FBX stays in centimeters, and the receiving app may read the numbers as meters or millimeters. Scale it on import.

OBJ file is very large

OBJ is text, so it's several times bigger than the same mesh in binary FBX. That's normal. Zip it if you need to send it.

FBX vs OBJ in short

FBX is a scene format: hierarchy, bones, animation, cameras, lights and materials, in a binary container owned by Autodesk. OBJ is a mesh format from the late 1980s that anyone can read and write with a few lines of code. Going from FBX to OBJ is a deliberate step down. You lose everything except the surface, and in return you get a file nothing will refuse to open.

If the end goal is a 3D print, go straight to FBX to STL, which also fixes the up axis for slicers.