OBJ is a plain-text mesh format from the world of computer graphics. It stores vertices, normals, texture coordinates and polygon faces, and nearly every 3D application — Blender, Maya, 3ds Max, game engines, renderers — can read and write it, making it a dependable lowest common denominator for mesh exchange.
Blender, Maya, 3ds Max, ZBrush, Cinema 4D and nearly every asset store export OBJ, and scanning tools use it as a neutral output. It is the plain-text lowest common denominator of mesh exchange, which is why it is still everywhere.
Best for: Exchanging textured meshes between modeling and rendering tools. There is a fuller write-up on the OBJ format reference page.
Every format on this site also gets the same viewport tools: orbit, pan and zoom with fit-to-view, isometric and the six standard views, a perspective/orthographic toggle, shaded, shaded-with-edges, wireframe and X-ray display, hide-selected, and a PNG screenshot of the current view. The same controls are on the general 3D and CAD viewer, which accepts every importable format at once.
Worth knowing before you rely on it. A viewer that overstates what it can read wastes more of your time than one that is specific about its limits.
| OBJ files | |
|---|---|
| Extensions | .obj |
| Geometry | Polygon mesh |
| Units | No |
| Colors & materials | Via MTL sidecar |
| Animations | No |
| Typical use | DCC tool interchange |
OBJ has no unit declaration, so the dimension readout shows the file’s own numbers with a millimetre label. Compare it against a known feature if the scale matters.
OBJ can be both read and written here, so the useful conversions are into formats that keep materials in one file, or into a printable mesh. The converter runs on the same local pipeline as this viewer, so a conversion is just as private as a preview: OBJ to GLB is the usual choice.
No. The page only receives the single file you drop, and it does not fetch neighbouring files from your disk, so materials and textures cannot be resolved. If appearance matters, convert the model to GLB in a tool that has all the files, since GLB packs geometry and materials into one file.
Because its color lives in the .mtl sidecar, which is not part of the file. The geometry, groups, counts and dimensions are all exactly as authored — only the material assignment is missing.
Yes. Each o or g group becomes its own entry in the tree with its own visibility toggle and its own properties, so a multi-part OBJ is inspectable piece by piece.
No. Parsing happens in a Web Worker in your browser. The text of the file is never sent anywhere.
Geometry: polygon mesh. Units: no. Colors and materials: via mtl sidecar. Animations: no. Of that, the viewer draws geometry and flat base colors; texture maps and animation are never displayed. OBJ has no unit declaration, so the dimension readout shows the file’s own numbers with a millimetre label. Compare it against a known feature if the scale matters.
Read the OBJ format reference for the format itself, open the general 3D and CAD viewer if you have several formats to look at, or start from the 3D and CAD converter.
If the model is heavier than it needs to be, the mesh simplifier reads .obj directly, decimates it in your browser and previews the result before you export. If the file is headed for a 3D printer, the G-code viewer shows the sliced toolpath layer by layer once your slicer has run.