FileConvert

3D model converter

STL to OBJ Converter

Turn STL files into OBJ without installing anything. The target format on this page is already set to OBJ, so a single file or a whole folder is one press of Convert away.

  • Whole batches at once
  • Quality you control
  • Removed once it is done

STL OBJ

or drop files here

Files travel over TLS and are deleted from the server as soon as the conversion finishes.

STL and OBJ: what actually changes

STL is a bare triangle soup, and the format every 3D printer slicer expects. OBJ is plain-text geometry with an .mtl sidecar for materials — universal, and very old.

Meshes, normals and UV coordinates are translated between the two scene descriptions rather than re-tessellated, so the geometry you get out is the geometry you put in. The OBJ you get back keeps vertices, normals, UVs and material references, and gives up animation, rigs and scene hierarchy. Check materials and texture paths afterwards — that is where STL and OBJ disagree most.

How it goes3 steps

  1. Add your STL files
    Drop them onto the box above or click Select File. Add as many .stl files as you like — the whole batch converts in one go, and duplicates are ignored.
  2. Confirm OBJ as the output
    OBJ is already selected as the target format on this page. Tweak the options if you need something other than a straight OBJ file.
  3. Download your OBJ
    Hit Convert and grab the finished OBJ files individually or as a single ZIP. Everything is deleted from the server once you have them.

Format facts

What each side of this conversion is good at, so you know what you are trading away.

Source .stl

STL

A bare triangle soup, and the format every 3D printer slicer expects.

Compression
Lossy
Transparency
Not supported
Keeps
Watertight surface geometry
Gives up
Colour, UVs, materials and normals

Result .obj

OBJ

Plain-text geometry with an .mtl sidecar for materials — universal, and very old.

Compression
Lossy
Transparency
Not supported
Keeps
Vertices, normals, UVs and material references
Gives up
Animation, rigs and scene hierarchy

Send STL somewhere else

Every other format a STL file can leave as.

From .stl 7 targets

fbx dae ply gltf glb 3ds x3d

Related converters

Other routes in and out of these formats.

FBX OBJ FBX to OBJ DAE OBJ COLLADA to OBJ PLY OBJ PLY to OBJ GLTF OBJ glTF to OBJ GLB OBJ GLB to OBJ 3DS OBJ 3DS to OBJ X3D OBJ X3D to OBJ

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