Fix any STL. In one click.
Diagnoses non-manifold edges, holes, degenerate faces, and duplicate vertices - then auto-repairs them. Hand the clean file straight back to the Meshcast mold generator without re-uploading.
Drop your STL
Binary or ASCII, up to ~100 MB. Stays in your browser - we never see the file.
Auto-diagnose
Non-manifold edges, holes, flipped normals, degenerate triangles - all flagged in seconds.
Fix & download
Auto-repair runs locally. Compare original vs fixed side-by-side, then download or send straight to Meshcast.
Results
Adjust optimization
FAQ
What's a "non-manifold edge"?
An edge that three or more triangles share, or a triangle whose normal points the wrong way. Slicers can't tell inside from outside on a non-manifold mesh and either refuse to slice it or produce a mess. The auto-fix re-stitches the geometry so every edge is shared by exactly two triangles.
Will the auto-fix damage my model?
For sculpted / scanned models, no - VCGlib's repair preserves the visible surface. For models with very narrow or hair-thin features (under 0.2 mm), some detail may smooth out. Compare Original vs Fixed in the viewer before you download.
What if the auto-fix can't repair the file?
Some failure modes are too severe (e.g. dozens of overlapping shells from a CAD export). Open the file in your slicer's repair tool or Blender (3D-Print toolbox) and re-export, then drop the result here.
Does the file leave my computer?
No. Repair runs inside your browser via WebAssembly. The file is loaded into memory, fixed, and the download is generated on your device. We never see your model.
Why is the file size smaller even with no simplification?
Most STL exporters write every triangle as an independent unit with three full vertex copies. Welding duplicates alone typically cuts file size by ~50 %.