Repair mesh

A full pre-print checkup: duplicate vertices, holes, loose shells, degenerate triangles and face orientation — with automatic repair of whatever is fixable.

What this tool does

How it works

  1. 01

    Upload the broken model

    That STL your slicer flags in red or prints with weird gaps.

  2. 02

    Read the diagnosis

    A concrete list of defects found: how many duplicates, holes and shells.

  3. 03

    Repair and download

    One click applies every fix and you download a closed, print-ready mesh.

Frequently asked questions

What defects can it fix?

Duplicate vertices, small and medium holes, degenerate triangles, flipped normals and loose fragments. Huge holes or complex self-intersecting geometry may need an editor like Blender.

Why does my STL 'look fine' but the slicer rejects it?

Viewers will render any triangle soup, but a slicer needs a closed, consistently oriented surface to compute what's inside. Defects invisible to the eye — flipped normals, unmatched edges — break that computation.

Does repairing change the model's shape?

Minimally: welding duplicates and closing small holes doesn't alter visible geometry. The one notable change is that UVs (texture coordinates) are dropped — irrelevant for printing.

What is a shell and why delete small ones?

A shell is a connected piece of the mesh. Scans often carry microscopic floating fragments that confuse slicers; only fragments orders of magnitude smaller than the main part are removed.