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Online STL to STEP Converter

Drop an STL file to preview it in 3D and download it as STEP, ready to open in your CAD program. Everything runs in your browser: nothing is uploaded.

Drop your STL file hereor click to choose a file. It never leaves your device.

How to convert STL to STEP

  1. 1

    Drag your STL file onto the box above, or click it to choose a file.

  2. 2

    Check the model and its dimensions in the 3D preview.

  3. 3

    Rotate it 90° if you need another orientation in your CAD.

  4. 4

    Click “Download STEP” and open the file in SolidWorks, Fusion 360, FreeCAD, Onshape or Inventor.

Tips for good results

  1. 1

    Models with fewer triangles give lighter files that open faster. Simplify very dense scans before converting.

  2. 2

    To get real cylinders and planes, rebuild the important features in your CAD program using the faceted STEP as a reference.

  3. 3

    Check that the mesh is closed: only closed meshes become solids.

What a faceted STEP is

An STL only has triangles; a STEP made in CAD has real surfaces such as planes, cylinders and fillets. Converting a mesh cannot invent those surfaces, so each triangle becomes a flat face. The result is called a faceted STEP.

If the mesh is closed, it is saved as a solid, so your CAD program can measure it, cut it, add holes or combine it with other parts. If it has holes, it is saved as a surface.

Frequently asked questions

Is the STL to STEP converter free?

Yes. You can convert files for free, without an account and without watermarks.

Are my files uploaded to a server?

No. The STEP file is created entirely in your browser, so confidential parts never leave your device.

Will I be able to edit the model in SolidWorks or Fusion 360?

Yes, as a solid made of flat faces: you can measure, cut, drill and combine it. Curved surfaces stay faceted, because an STL does not contain them.

Why is the STEP file so large?

Each triangle becomes a face with its own geometry, so STEP files are bigger than the STL. Simplifying the mesh first reduces the size.

What units does the STEP use?

Millimeters. STL files have no units, so millimeters are assumed, and the STEP declares them so CAD programs open it at the right size.