Upload a 3MF, STL or OBJ and cut the model: with a plane, a line or an outline drawn right on its surface — that is how you cut off an ear, an arm, a tail. A model too big for the printer can be split to fit the bed. A plug joint or pins for assembly. The file is processed in your browser.
How to split an STL into parts online
The model is too big for your printer bed, a figurine has ears and arms that only print with supports, or one detail should be a different color — in all these cases it is easier to split the model into parts and assemble it after printing. This STL splitter cuts 3MF, STL and OBJ files right in your browser: nothing to install, and the file is never uploaded.
Four ways to cut
- Plane — the classic cut: split a 3D model in half or anywhere you need. The plane can be moved and tilted.
- Line — place points, a smooth line runs through them and the knife goes through the model the way you look at it. An open line splits the model in two, a closed outline cuts out what is inside.
- Surface — draw an outline right on the model, for example around an ear or a tail, and close it on the first point. The outlined part becomes a separate piece.
- To bed — set the bed size under Print area and the model is split into as many parts as needed for each to fit. Every cut shifts to where the model is thinner, with a joint on every seam.
Connectors: plug joint, dovetail and pins
So the parts need no fitting and do not slide while gluing, the cut gets a connector.
- Plug — the part goes into the model with a flat-bottomed plug, with a matching socket in the model. The flat bottom is what the part lies on when printing, and the walls taper at no more than 45°, so it prints without supports.
- Dovetail — the part slides into a slot from the side and cannot be pulled out upwards. Available for plane cuts.
- Pins — separate (printed on their own, holes in both parts) or built-in (grow out of one part, a hole in the other).
- Flat — a simple flat cut for gluing.
Clearance for your printer
Clearance is set per side: 0.15 mm is tight, 0.2 mm normal, 0.3 mm loose. If parts fit too tight, increase it and download again. Plug depth, rim, bottom area and pin diameter can be adjusted under Fine-tune.
How the part lies on the bed
For plane and surface cuts the part can lie cut side down — a flat base to print on — or stay as in the model.
What you get
The parts download as one 3MF or a ZIP with separate STL files. Open them in Bambu Studio, Orca Slicer, PrusaSlicer or Cura and print as usual, each in its own filament.
FAQ
How do I split an STL into parts for 3D printing?
Upload the file, choose how to cut — plane, line, surface or to bed — add a plug or pins if you need them and press Cut. The parts download as one 3MF or a ZIP with separate STL files.
Do I need to install anything?
No. The model is processed in your browser and is never uploaded.
How do I split a model that is too big for my printer?
Choose the To bed mode and set your bed size — the model is split into parts that fit the bed, with a joint on every seam.
What clearance should I use for the plug and pins?
0.2 mm per side works in most cases. 0.15 mm for a tight fit, 0.3 mm for a loose one.
Which files can I upload?
3MF, STL and OBJ up to 3,000,000 triangles.
Can I cut off a single part — an ear, an arm, a tail?
Yes, with the surface mode: outline the part with points right on the model and close the contour. The part has to be attached to the model in one place, so a single line can separate it.