Check and repair STL files
Slicers fail on open or broken meshes. See exactly where the holes are, then download a cleaned STL with merged vertices and fixed normals.
Private
Files are processed on your device and never sent to a server.
Free, no account
No sign-up, no watermark, no daily limits.
Nothing to install
Works in Chrome, Edge, Firefox and Safari on desktop and mobile.
How it works
- 01
Drop an STL, OBJ, PLY or 3MF file.
- 02
Click “Check”: holes are shown as red lines on the model.
- 03
Download the repaired STL.
Questions
What does the repair fix?+
It merges duplicate vertices, removes degenerate triangles, recalculates normals and flips an inside-out mesh.
Does it fill holes?+
Small gaps often close after merging vertices. Large holes need a modeling tool; the checker shows where they are.
In what units is the volume?+
In the file’s units cubed — usually mm³ for 3D printing files.
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