# Free online OBJ viewer

> View OBJ 3D models in your browser with their MTL materials and textures. Drop the .obj with its .mtl and images, or a ZIP — free, no upload. Mes3D names any file that is missing.

Source: https://freestlviewer.com/obj-viewer/  
Updated: October 22, 2026

Open .obj models with their materials and textures. Drop the whole folder or a ZIP, and if a .mtl or image is missing, Mes3D tells you which one. The tool is interactive: open https://freestlviewer.com/obj-viewer/ and drop a file onto the page.

## OBJ in one paragraph

Wavefront OBJ is a plain-text format from the late 1980s that is still one of
the most widely exchanged 3D formats. It lists vertices (`v`), texture
coordinates (`vt`), normals (`vn`) and faces (`f`), and unlike STL it supports
quads and larger polygons, shared vertices and UV mapping. What it does **not**
contain is colour: materials live in a separate `.mtl` file, referenced by a
`mtllib` line, and the `.mtl` in turn references image files for textures.

So an OBJ "model" is often three or more files that only work together.

## Why OBJs lose their textures

The most common problem with OBJ is not the geometry — it is the companions.
Someone emails you `chair.obj`, but the `chair.mtl` and `wood_diffuse.jpg` it
depends on were left on their disk. Most viewers then show a grey mesh without
saying why.

Mes3D reads the `mtllib` line, looks for each material library and every
texture the library names, and if one is missing it tells you the file name.
That turns "it looks wrong" into "ask them for `wood_diffuse.jpg`".

## How to open an OBJ with its materials

1. Put the `.obj`, `.mtl` and texture images together — usually they already
   sit in one folder.
2. Drag **the whole folder**, all the files at once, or a **ZIP** of them onto
   the drop zone above. Clicking **Choose 3D file** and selecting several files
   works too.
3. The model opens with its materials. Pick **Original** as the model colour to
   see them, or any solid colour to inspect the bare shape.
4. Rotate, zoom, pan and use preset views; on a computer, measure distances
   and open the mesh analysis.

If you only have the `.obj`, open it on its own — the geometry is all there,
just without colour.

## What Mes3D does with the geometry

- Quads and n-gons are triangulated for display; the original file is not
  changed.
- Multiple groups and objects in one OBJ are shown together.
- The bounding-box size and triangle count are shown in the dimensions panel.
- Volume, surface area, estimated print weight, watertightness and overhangs
  are computed from the triangles — useful when an OBJ is headed for a 3D
  printer.

Because OBJ has no unit, all sizes are read as millimetres. Models from
animation and game tools are often in centimetres or metres; a "2 mm tall
person" is a metre-scale export, not a broken file.

## OBJ, STL or glTF?

| Need | Best choice |
| --- | --- |
| Send geometry to a 3D printer | STL or 3MF |
| Move a textured model between modelling tools | OBJ (with its .mtl and images) |
| Show a textured model on the web or in AR | glTF / GLB — one file, PBR materials |
| Keep units and colours for printing | 3MF |

OBJ's weakness is that it is a folder rather than a file. If you are the one
sending it, zip the folder; if you are publishing to the web, convert to GLB.

## On a phone

In a mobile browser you can open an OBJ (or a ZIP containing one), rotate and
zoom it and read its dimensions. The Mes3D app for iPhone, iPad and Android
opens OBJ files from Files, Mail or chat attachments, adds measuring, mesh
analysis and cross-sections, and can export a resized or cut model as OBJ,
STL or 3MF. On iPhone and iPad it adds AR too, and once it is installed `.obj`
files get a 3D preview and thumbnail in the Files app.

## Limits

- Up to 200 MB per file in the browser.
- Texture images must be in a format the browser can decode (PNG, JPEG, WebP
  and similar). TGA and DDS textures referenced by older exports may not show.
- Only the materials an `.mtl` defines are used; renderer-specific shaders from
  the source application are not.

## Frequently asked questions

### Why does my OBJ show up grey with no textures?

OBJ keeps its materials in a separate .mtl file, and the .mtl points to separate image files. If you open only the .obj, the viewer has no colours or textures to show. Drop the .obj together with its .mtl and texture images, or the folder or ZIP they came in.

### Can I open an OBJ in a ZIP file?

Yes. Drop the ZIP straight onto the viewer; Mes3D finds the .obj inside, then its .mtl and textures by the paths the files reference.

### What units does OBJ use?

None. OBJ stores bare numbers, so the unit depends on the program that exported it. Mes3D assumes millimetres for dimensions and analysis; if a model looks 25.4 times too small, it was probably exported in inches.

### Are my files uploaded?

No. The .obj, .mtl and images are read in your browser and never sent to a server.