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PhotoGenius

Free 3D converter

Convert STL to OBJ

Drop a STL file and download it as OBJ. The conversion runs in your browser, so the file never leaves your device. It keeps the exact shape.

Free, no sign-up, and your file stays on your device.

Drop a STL file here

Converted to OBJ in your browser. Nothing is uploaded.

GLB, glTF, OBJ, STL, PLY, FBX or 3MF, up to 300 MB. Add .mtl, .bin and texture files alongside.

What carries over from STL to OBJ

Checked against what the converter writes, not just what the formats allow.
Shape (triangles)
Kept exactly
UV coordinates
Not in STL
Colour texture
Not in STL
PBR maps (roughness, metalness, normal)
Not in STL
Vertex colours
Not in STL
Animation
Not in STL
Separate parts
Not in STL
Size and units
Written in millimetres; OBJ doesn't record units.
Up direction
Turned Y up, so the model stands upright in viewers.

How to convert STL to OBJ

  1. Add your STL

    Drop the .stl file or choose it from your device.

  2. Check the preview

    Turn the model and check what will be kept before converting.

  3. Download the OBJ

    The .obj (or a .zip with textures) is written in a second or two for most models.

When to convert STL to OBJ

  • For an app that doesn't read your format

    OBJ is the lowest common denominator: almost every 3D app (Blender, Maya, 3ds Max, Cinema 4D, ZBrush), Unity and Roblox Studio natively, and every major slicer.

  • To edit the mesh

    Plain-text geometry with UVs is easy to inspect, clean up and re-import.

The two formats

STL

Stereolithography

STL was created by 3D Systems in 1987 for its stereolithography printers. It stores a surface as a list of triangles and nothing else: no colour, textures or units.

Usually comes from
print libraries such as Printables and Thingiverse, CAD exports and 3D scanners
Opens in
every slicer (Bambu Studio, PrusaSlicer, OrcaSlicer, UltiMaker Cura and others) and most 3D apps
Units
None recorded (read as millimetres by slicers)
Up axis
Z up by convention

OBJ

Wavefront OBJ

OBJ is the plain-text mesh format Wavefront Technologies introduced in the late 1980s. It stores vertices, UVs, normals and faces; materials and texture maps live in a companion .mtl file.

Usually comes from
older asset libraries, CAD and DCC exports, and photogrammetry apps
Opens in
almost every 3D app (Blender, Maya, 3ds Max, Cinema 4D, ZBrush), Unity and Roblox Studio natively, and every major slicer
Units
None recorded
Up axis
Not recorded (usually Y up)

Need a model to convert?

Make one with AI from a photo or a sentence, then download it as GLB and convert it here.

Questions

Something else? Ask us and a person will answer.

Is this STL to OBJ converter free?

Yes. There is no account, watermark or limit on conversions. It accepts files up to 300 MB; how large a model your browser can handle depends on your device's memory.

Is my file uploaded?

No. The conversion runs in your browser with the open-source three.js loaders and exporters, so your STL never leaves your device.

Are textures included in the OBJ?

If the model has a colour texture, you get a .zip with the .obj, its .mtl and the texture as PNG. Keep them in one folder when you import. OBJ has no standard for PBR maps, so roughness, metalness and normal maps are left out.

Can I make a 3D model from a photo instead?

Yes. PhotoGenius turns a photo or a text prompt into a textured GLB with Rodin Gen-2.5, Rodin Gen-2.5 Fast, Tripo H3.1, TRELLIS.2, Rodin Gen-2 or Hunyuan3D 3.1, which you can then convert here. See Image to 3D model.

Turn a photo into a 3D model

Rodin Gen-2.5, Rodin Gen-2.5 Fast, Tripo H3.1, TRELLIS.2, Rodin Gen-2 or Hunyuan3D 3.1 builds a textured GLB from one image. The price shows before you run it.

Make a 3D modelAbout the 3D generator