What is a .obj file?
Wavefront 3D Object · 3D model · Wavefront Technologies · 1990s
OBJ is a widely supported 3D model format that stores geometry plus optional texture coordinates, and it can reference materials in a companion MTL file. It is a common interchange format between 3D applications.
What is a .obj file used for?
An OBJ is plain text listing vertices, texture coordinates and faces. It can point to an accompanying .mtl file that defines colours and textures.
Because it is simple and text-based, almost every 3D tool imports and exports OBJ, making it a reliable way to move models between programs.
It does not store animation or rigging, so for game and film pipelines richer formats like FBX or glTF take over.
What opens a .obj file?
The .obj format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Blender
- Windows 3D Viewer
- MeshLab
macOS
- Blender
- Preview (view)
- MeshLab
Linux
- Blender
- MeshLab
Web
- Online 3D viewers
Open a .obj file step by step
- Confirm the file really is a .obj. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Blender or Windows 3D Viewer.
- On Mac, use Blender or Preview (view).
- On Linux, try Blender or MeshLab.
- Still stuck? Convert the .obj to STL, which opens more widely.
Why can't I open my .obj file?
Almost always because no installed app understands OBJ. 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 .obj 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 .obj file
You can convert a .obj file to STL, FBX, GLTF using a conversion tool or the export menu of an app that opens it.
OBJ has no fixed magic number, so there is no signature table on this page. Its bytes alone do not prove the format: identification relies on the extension, the structure of the content and the program that created it. The magic-numbers reference lists the formats that do carry one.
Frequently asked questions
What is a .obj file?
OBJ is a widely supported 3D model format that stores geometry plus optional texture coordinates, and it can reference materials in a companion MTL file. It is a common interchange format between 3D applications.
Why is my OBJ model missing its colours?
OBJ stores textures and materials in a separate .mtl file, plus image files. Make sure those travel alongside the .obj.
Related formats
Sources
Details on this page were checked against authoritative references. How sources are ranked and what is deliberately left out is set out in the methodology.