I built this because every free STL→STEP converter I tried handed back a file that opened in Fusion and then refused to do anything — no fillets, no shell, no offset. The converters don't lie exactly, they just don't tell you that wrapping triangles in a shell isn't the same as a solid. So the tool checks first and shows you. Watertight or not, manifold or not, how many solids came out versus went in, with a 3D preview of the actual result. Then you decide whether it's worth paying for. Preview is free; you only pay for a file you've already seen. It won't recover design intent — nothing can reconstruct a feature tree from a mesh, and I say so on the page rather than pretending otherwise. Happy to answer anything about the geometry side.

StlFixTool

Convert and repair 3D and CAD files, pay per file

Convert and repair 3D and CAD files, pay per file