OBJ File Format (.obj)
An OBJ file is a plain-text 3D geometry format that Wavefront Technologies designed for its Advanced Visualizer software, storing vertex positions, texture coordinates and normals as human-readable lines of ASCII text.
OBJ at a glance#
| Full name | Wavefront Object |
|---|---|
| File extension | .obj |
| Category | 3D Models |
| Developer | Wavefront Technologies |
| MIME types | model/obj |
| Compression | Uncompressed |
| FileFlip support | FileFlip reads and writes this format |
What a .obj file can hold#
These are the things a OBJ file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Textures and materials | Yes |
|---|---|
| Human readable | Yes |
| Comments | Yes |
Strengths and limitations of OBJ#
What OBJ does well
- Plain ASCII text that any editor or script can read and modify by hand
- Near-universal support, effectively every 3D application on every platform can read it
- The companion MTL file keeps material definitions just as readable as the geometry
Where OBJ falls short
- No skeleton, skinning or animation support, so rigged characters need a different format
- Materials live in a separate MTL file, so a copied OBJ without its MTL loses its look
- Text encoding makes large, dense meshes far bigger on disk than an equivalent binary format
Use OBJ when a static mesh needs to move between two different applications with the least risk of anything being misread.
Convert away from OBJ when the model needs animation, a skeleton, or to travel as a single file without a companion MTL.
How to open a .obj file#
A .obj file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts OBJ 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, 3ds Max, MeshLab |
| macOS | Blender, Cinema 4D, MeshLab |
| Linux | Blender, MeshLab |
| Web | FileFlip, Sketchfab |
OBJ questions people ask#
What is an OBJ file used for?
An OBJ file stores the geometry of a single 3D model: its vertices, faces, texture coordinates and normals, written as plain text. It's used to move a static mesh between applications, since almost every 3D tool on every platform can read it.
Why does converting an OBJ file produce a ZIP?
An OBJ file only holds geometry; its material definitions, including which texture image goes where, live in a separate companion MTL file that the OBJ references by name. A converter has to hand back both files together, which is why an OBJ export comes as a ZIP rather than a single file.
Can OBJ files have animation?
No, OBJ has no concept of a skeleton, bone weights or keyframes, so it cannot store animation of any kind. It only describes a static mesh at one point in time; formats like FBX or glTF are needed for anything that moves.
Does OBJ support color and materials?
OBJ itself stores no colour or material data at all; that information lives in the companion MTL file it references, which defines diffuse and specular colours, transparency and texture maps using the Phong reflection model. Without the matching MTL file, an OBJ opens as a plain grey mesh.
Converting OBJ files#
Convert OBJ to another format
Convert another format to OBJ
- 3DS to OBJ
- COLLADA to OBJ
- FBX to OBJ
- STL to OBJ
- GLB to OBJ
- glTF to OBJ
- PLY to OBJ
- 3MF to OBJ
- AC3D to OBJ
- AC3D Scene to OBJ
- ACC to OBJ
- AMF to OBJ
- ASE to OBJ
- ASK to OBJ
- B3D to OBJ
- BLEND to OBJ
- BSP to OBJ
- BVH to OBJ
- COB to OBJ
- CSM to OBJ
- DirectX X to OBJ
- DXF to OBJ
- ENFF to OBJ
- HMP to OBJ
See every 3D model conversion (40 more)
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.