.obj

What is a .obj file?

OBJ is a simple, widely supported 3D model format — storing geometry in plain text, common for 3D printing and game assets.

Safe format
Type Cad
By Wavefront Technologies
MIME model/obj

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What is it

You downloaded a 3D model from a marketplace, a scan service, or a tutorial. It's an OBJ file — probably the simplest widely-supported 3D format in existence. OBJ stores geometry (vertices, faces, normals, texture coordinates) in plain text. Open one in a text editor and you can literally read the coordinates.

Wavefront Technologies created OBJ in the 1980s for their Advanced Visualizer software. The format's survival is entirely due to its simplicity — no proprietary encoding, no binary blobs, just structured text that any programmer can parse in an afternoon. OBJ files are typically paired with .mtl (material) files that define colours, textures, and surface properties. The limitation is that OBJ doesn't support animation, rigging, or scene hierarchy — it's static geometry only.

Blender (free), MeshLab (free), and Windows 3D Viewer all open OBJ files. Every CAD and 3D application can import and export OBJ. For 3D printing, OBJ works but STL is more standard. For web delivery, convert to glTF. OBJ is the format you use when you need maximum compatibility and don't need animation.

Technical details
Full Name
Wavefront OBJ
MIME Type
model/obj
Developer
Wavefront Technologies
Magic Bytes
N/A
Safety
.obj is a known, safe format.
What opens it
Blender
FREE All
Windows 3D Viewer
FREE Windows
MeshLab
FREE All
FAQ
What's the difference between OBJ and STL?
OBJ supports texture coordinates, normals, and material references (.mtl files). STL only stores triangle geometry — no colours, no textures. For 3D printing, STL is standard. For rendering and visualisation, OBJ carries more information.
Can I 3D print an OBJ file?
Yes. Most slicers (Cura, PrusaSlicer) accept OBJ files alongside STL. Just make sure the mesh is watertight (no holes) and correctly scaled. OBJ files don't carry unit information, so double-check the dimensions.
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