What does the sample model look like?

A gently rolling surface, like a patch of terrain, built from triangles. It has no materials or textures.

What is the MIME type of an OBJ file?

The MIME type is model/obj. The file extension is .obj.

Is a sample OBJ file the same as a dummy or example OBJ file?

Yes. Sample, test, dummy and example OBJ files are different names for the same thing: an OBJ file with known contents that stands in for a real one. Any file on this page will do wherever a tutorial or a test plan asks for a dummy OBJ file.

Free OBJ sample files

A plain-text 3D geometry format listing vertices and faces. Supported by nearly every 3D tool. Download valid OBJ test files in 4 exact sizes, from 1 KB to 1 MB, each with a checksum.

Extension: .obj
MIME type: model/obj
Kind: Text
Category: 3D Models

OBJ files by size

Every file below is a valid Wavefront OBJ 3D model file of exactly the stated size. Open a file's page for its checksum and contents, and to preview it in your browser before downloading.

OBJ sample files by size
File	Size	Contents	Download
1 KB OBJ samplesample-obj-1kb.obj	1 KB1,024 bytes	Vertices: 27	Download OBJ
10 KB OBJ samplesample-obj-10kb.obj	10 KB10,240 bytes	Vertices: 231	Download OBJ
100 KB OBJ samplesample-obj-100kb.obj	100 KB102,400 bytes	Vertices: 1,944	Download OBJ
1 MB OBJ samplesample-obj-1mb.obj	1 MB1,048,576 bytes	Vertices: 17,700	Download OBJ

What is an OBJ file?

An OBJ file describes a 3D mesh as text. Lines beginning with "v" define vertex positions, and lines beginning with "f" define faces by referring to those vertices by number.

Materials live in a separate .mtl file, and there is no support for animation or scene hierarchy. That simplicity is why OBJ remains a common exchange format.

How to recognise an OBJ file

No signature bytes. OBJ files are identified by parsing their content.

Extension	.obj
MIME type	model/obj
Origin	Wavefront Technologies
Encoding	ASCII text
Indexing	Vertex numbers start at 1
Companion file	.mtl for materials

What to test for

These are the behaviours that most often go wrong when software handles OBJ files.

Face indices are one-based and can be negative, meaning relative to the end of the vertex list; importers written for zero-based arrays are off by one.
OBJ has no unit of measurement, so the same file can appear at wildly different scales in different tools.

Strengths of OBJ

Supported by practically every 3D application.
Plain text that is easy to generate and inspect.

Limitations of OBJ

No animation, scene hierarchy or units.
Large and slow to parse compared with binary mesh formats.

Typical uses of OBJ test files

Testing 3D model upload and preview
Checking mesh importers and converters
Load-testing viewers with large meshes

Software that opens OBJ

Blender, Maya and 3ds Max
MeshLab and three.js
Slicers for 3D printing

Specifications

OBJ format reference (Paul Bourke)

OBJ sample files: questions

What does the sample model look like?: A gently rolling surface, like a patch of terrain, built from triangles. It has no materials or textures.
What is the MIME type of an OBJ file?: The MIME type is model/obj. The file extension is .obj.
Is a sample OBJ file the same as a dummy or example OBJ file?: Yes. Sample, test, dummy and example OBJ files are different names for the same thing: an OBJ file with known contents that stands in for a real one. Any file on this page will do wherever a tutorial or a test plan asks for a dummy OBJ file.