Check and fix meshes before slicing: STL, OBJ, 3MF. Everything runs in your browser.
Auto repair welds duplicate vertices, drops broken triangles, makes faces point outward and fills holes. Merge shells joins overlapping parts into one clean solid.
Uses the overhang angle next to the viewer (45° is typical for PLA). Auto orient picks the rotation with the least overhang.
Merges triangles while keeping the surface within the tolerance. 0.02–0.1 mm is invisible on most prints.
For resin prints. Works on meshes up to 8,000 triangles (Reduce first); can take a minute.