nozzlefox

OBJ

OBJ viewer

Open OBJ files with their MTL colours, fix units and orientation, and measure in mm.

  • Nothing uploaded
  • No sign-up
  • Free, no limits

Drop your OBJ file here (and its .mtl)

or paste it, or pick it from your device

.obj · .mtl

  1. Drop your OBJ file
  2. Check it in 3D
  3. Explore the model

Good to know

How to open an OBJ file

  1. Drop the .obj above. To see colours, drop its .mtl file together with it.
  2. Check the size and orientation. Fix units or the up axis in the panel if needed.
  3. Toggle objects and groups in the list, and measure in mm.
  4. Download as STL or 3MF (keeps the object colours) for printing.

Why OBJ files open too big or too small

OBJ files store plain numbers with no unit. A model built in metres (Blender's default) has numbers like 0.1, which a slicer reads as 0.1 mm, so it arrives 1000× too small. Inch models arrive 25.4× too small. This tool guesses from the numbers (tiny numbers usually mean metres), shows its guess, and lets you pick mm, cm, m or inches, or simply set the size you want.

Why it lies on its side

3D printing uses Z as “up”, but Blender's OBJ export and most 3D apps write Y as up. Files are treated as Y-up by default and turned upright; if your model was made Z-up (common from CAD), switch to Z up.

Materials, colours and textures

OBJ keeps colours in a separate .mtl file, which the OBJ refers to by name. If the model shows up grey, the MTL wasn't included: you'll see a note naming the file it needs. Material colours and per-vertex colours are shown. Image textures aren't, since they can't be printed from an STL anyway.

Can you 3D print an OBJ?

Yes. UltiMaker Cura, PrusaSlicer, OrcaSlicer and Bambu Studio all import OBJ (PrusaSlicer ignores its materials). The safest route is converting to STL or 3MF with the OBJ to STL converter, which fixes the size and orientation first.

Questions

How do I view an OBJ file online?

Drop it (and its .mtl file for colours) into the viewer at the top of this page. It opens in your browser with nothing uploaded.

Why is my OBJ grey with no colours?

OBJ stores colours in a separate .mtl file. Drop the .mtl together with the .obj. The viewer names the file the OBJ is asking for.

Why is my OBJ tiny or huge?

OBJ has no units. Models made in metres look 1000× too small in millimetre software. Pick the right unit in the panel, or set the size you want directly.

My model is lying on its side. How do I fix it?

Switch the up axis between Y up and Z up. Most 3D apps and Blender export Y-up; 3D printing and CAD use Z-up.

Can an OBJ file be 3D printed?

Yes. Most slicers import OBJ, but converting to STL or 3MF here first makes sure the size and orientation are right.