3D Quality ToolsFree mesh preflight
Check an STL file for common mesh problems before 3D printing, including open edges, non-manifold geometry, duplicate triangles and orientation issues.
Select a .stl file.
Select a non-empty .stl file.
A mesh quality check can flag topology and orientation problems early, helping you avoid failed slicing or unexpected gaps in a print. Submit your STL above to start a job. The report appears automatically when the analysis finishes.
Upload an STL and InspectMesh checks its triangles, edges and surface orientation for common mesh problems.
Open edges and non-manifold edges can prevent a clean solid. Duplicate or degenerate triangles add invalid geometry, while orientation issues can affect inside and outside calculations. Ready for slicing means these checks found no listed mesh blockers, not that every printer setting is correct.
It is an edge used by only one triangle, often indicating a hole.
It has no usable area because its vertices collapse together or lie on a line.
Usually yes, because overlapping faces can confuse downstream tools.
STL Manifold Checker · STL Watertight Checker · All STL tools