Free local tool

STL Viewer

Inspect an ASCII or binary STL file locally with a bounded interactive 3D wireframe preview and mesh summary.

Private by design: inputs and local files stay in this browser tab. The tool sends no input to a server and stores nothing after the page closes.

JavaScript is required for the interactive tool.

Method and limits

Supports ASCII and strict 84 + 50×triangle-count binary STL structure, up to 50 MB and 200,000 triangles. Face normals are recomputed for deterministic display. STL coordinates are unitless unless external context defines units. This viewer does not prove watertightness, manifold topology, printability, repair, or structural integrity.