STLRepair

STLRepair helps makers and 3D printing users check STL files before slicing. It analyzes open boundaries, non-manifold edges, normal mismatches, duplicate faces, and degenerate triangles locally in the browser. Users can apply conservative cleanup, verify the output, and download the repaired STL. The free workflow supports binary and ASCII STL files up to 10 MB or 100,000 triangles without an account or file upload. Open holes and non-manifold topology are reported for manual review rather than reconstructed automatically.