Check STL for Printing
Open Edge & Normal Checker
Find the mesh defects that cause slicer warnings before you waste a print. Upload an STL to inspect open edges, non-manifold connections, face normal consistency and degenerate triangles.
Check STL files before printing
Most slicer errors point to a small set of mesh problems. This STL checker turns those problems into a short diagnostic report so you can decide whether to repair the file or continue to slicing.
What the STL checker looks for
- Open edges: Edges used by one triangle often reveal holes or an unclosed shell.
- Non-manifold edges: Edges shared by more than two faces can confuse slicers and Boolean operations.
- Face normals: Inconsistent winding can make surfaces appear inside out or create missing regions.
- Degenerate faces: Zero-area triangles add noise and may break downstream mesh tools.
Frequently Asked Questions
How do I check an STL for 3D printing?
Upload the STL, review open edges, non-manifold edges, normal consistency and degenerate faces, then inspect the highlighted mesh before slicing.
What is an open edge in an STL?
An open edge is used by one triangle instead of two. It often marks a hole, a missing surface or a boundary that can cause a slicer error.
What should STL normal consistency be?
A healthy closed STL should have consistently oriented face normals. A review status means the mesh needs attention before printing.