From mesh to CAD
Convert STL to STEP, right in your browser
Found a part you'd love to tweak, but it only comes as an STL? Turn it into a proper STEP file you can open and edit in your CAD program. No upload, no install, no extra software. Adjust how much detail to keep and tinker until it looks right.
How it works
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1
Open your file
Drop in an STL, 3MF or OBJ. Anything you'd normally send to your slicer works.
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Preview the faces
Coloured patches show how your model will be split into CAD faces. Pick the method that suits the part: Angle splits at sharp edges and works for most printed parts. Detected finds flat areas, cylinders, cones, spheres and rounded edges on its own. Faceted keeps every triangle as it is and always converts, which is closest to what most other converters do. A readout shows how much of the surface will become clean CAD faces.
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Pick a detail level
Standard is right for most parts. Switch to Extended or Maximum when a large or organic model needs more headroom.
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Export
Save a single .stp file and open it in your CAD program.
What the converter does
Rounded edges stay rounded
Fillets and rounds are recognised as their own curved faces instead of being lumped in with the flat surfaces next to them.
Finds the shapes for you
Detected mode picks out flat faces, cylinders, cones, spheres and blends across the whole model, with nothing to tune.
Know what you'll get before you export
See how much of your model will become clean, editable CAD faces and how much will stay as raw triangles.
Threads made simple
A printed screw thread is thousands of tiny triangles. Swap it for the plain cylinder underneath, then cut a fresh thread in CAD if you need one.
Three detail levels
Standard, Extended and Maximum trade a longer wait for better results on bigger models.
STEP files open too
Bring a STEP file in, choose how smooth it should look, and change that later without reloading the file.
Honest limits
You get an editable shape, not the original design. Faces are surfaces fitted to your mesh; there are no sketches, extrudes or feature history to step back through.
You can often improve the result by tinkering with the conversion options.
- Big models take time. Past roughly 50,000 faces a conversion can run for tens of minutes.
- Organic shapes such as sculpts and figures end up mostly as raw triangles. The result is exact, but the file is large and many CAD programs open it slowly.
- Faceted mode always works, but it keeps one flat face per triangle, so there is little you can edit afterwards.
See it in action
Video overview coming soon
FAQ
What file formats can I convert to STEP?
STL, 3MF and OBJ. You can also load a STEP file, adjust it, and export it again. If the app can open it as a mesh, it can convert it.
Is my file uploaded anywhere?
No. Everything stays in your browser. The file never leaves your device.
How does the conversion actually work?
The app looks at your mesh, finds the areas a CAD program would treat as single faces, and rebuilds them as proper CAD surfaces. A full CAD engine (OpenCascade.js) runs inside your browser tab, so nothing is sent to a server and there is nothing to install.
Will my CAD program open the file?
It exports a standard STEP file (.stp), the same kind CAD programs use to exchange parts with each other. Each object you select becomes its own solid.
Why does a heavy mesh take so long?
Turning thousands of faces into one watertight solid means stitching them together and fixing any gaps. On a very dense or organic model that clean-up grows quickly, so tens of thousands of faces can mean tens of minutes. Simpler parts convert in seconds.