Split STL into Parts

Open the STL and click Split into parts. Every piece of the mesh that does not touch another piece becomes its own part. Then download the ZIP to get one STL per part, or download the parts one at a time.

This tool separates pieces that are already disconnected in the file, such as the parts of a print-in-place kit or several models exported together. A single solid, like a statue, has no separate pieces to find. Cutting through solid geometry with a plane is a different operation that this page does not do yet.

A hollow model is stored as an outer surface plus an inner surface, which are technically two disconnected shells. By default, any shell whose bounding box fits inside another part's bounding box stays with that part, so a hollow box is not split into an outer and an inner skin. That check uses boxes, not exact shapes, so a loose piece sitting inside a ring, frame or open box is kept with it too. Turn off Keep inner shells with their part if you want every shell separately.

Pieces keep their original position from the assembly unless Spread parts out on the plate is on. With it on, each part is dropped onto the plate and laid out side by side. The geometry of each part is unchanged either way.

Download the ZIP when you want to print or share parts separately, or send them to a print service. Download a 3MF when you want to open all parts together in a slicer like PrusaSlicer, Bambu Studio or Cura; each part arrives as its own object you can move, scale and assign settings to.

No. Files are read and processed by JavaScript in your browser tab, and downloads are generated locally. Nothing is sent to a server, so it also works with private or unreleased designs.