Drag either model to rotate · zoom to inspect · switch to wireframe
triangles in both files
14,564
OBJ output
1.31 MB
numeric coordinate scale
1:1
A licensed sample converted with this tool. This is a format demo, not an AI-generated or verified print result. Model source & license · Made In Space, Inc. and NASA Marshall Space Flight Center · NASA media usage guidelines
STL vs OBJ: triangles for printing or a mesh for editing
The source STL supplies a triangle surface. Converting it to OBJ makes another mesh representation; it cannot recover the design that produced the triangles.
Source formatSTL
STL triangle surface
A collection of triangles describing the outside of a model. It is a common handoff format for 3D printing slicers.
Structure
Each triangle stores its own corner coordinates and face normal. Fomrix writes binary STL; it does not export CAD sketches or design history.
Color & texture
Standard STL has no texture image, UV layout or material package. A gray preview is expected even if the original was colorful.
Scale & units
STL does not store a unit. This tool writes the size you choose as millimeter coordinates; confirm it on import into a slicer.
Best suited to
Taking a verified surface into a slicer. An STL extension alone does not make an open or thin mesh printable.
Output formatOBJ
Wavefront OBJ
A text-based surface description built from vertex coordinates and faces. It is widely used to move meshes between modeling applications.
Structure
Vertices can be shared by faces; polygon faces are possible. This converter reads mesh faces and triangulates them, ignoring line and point primitives.
Color & texture
OBJ can reference an MTL library, UV coordinates and separate texture images. Those are format capabilities; this converter exports geometry without that package.
Scale & units
An OBJ generally does not declare a dependable physical unit. Check import scale and a known measurement in your next application.
Best suited to
Static mesh exchange and shape editing. Use an editor to prepare topology, UVs or materials for your final purpose.
Editable mesh does not mean editable CAD
You can move faces in an editor, but you cannot recover a forgotten sketch dimension or undo the original design steps from an STL.
What you can change
Inspect, clean, sculpt or retopologize the triangle surface in a mesh editor. Build UVs and materials separately if you want a render.
What conversion cannot recover
A STEP solid, mechanical feature tree, original quads and texture images are not hidden inside the STL. For those tasks, obtain the source project or reconstruct it.
From your file to the next step
Select a step to see what happens. Try the actual conversion above when you are ready.
No. STL contains a triangle approximation of the surface. Conversion cannot recover parametric features, exact CAD solids or the original design history.
Does the OBJ keep the STL's size?
It keeps the numeric vertex coordinates without scaling. STL and OBJ do not reliably describe the measurement unit, so match units in the application that imports the result.
Does STL to OBJ add colors or textures?
No. The output is geometry only. Add materials, UVs and textures in your editor when you need them.
