How to cut an STL in half
- Drop your STL (or OBJ, 3MF, STEP) into the box above.
- Pick the cut direction – X, Y or Z – and drag the slider or type the exact height in mm.
- Keep Add dowel holes on so the two halves line up when you glue them.
- Click Download pieces: each half is a separate, closed STL or 3MF.
Cut it into more pieces
Switch to Fit printer, choose your printer and the model is divided into the fewest equal pieces that fit – for example 2 × 1 × 3 for a 600 mm helmet on a 256 mm Bambu Lab bed. Every cut gets dowel holes. You can also run the plane cut again on a downloaded half.
Why cut a model before printing?
- Too big for the bed – the most common reason, from cosplay helmets to architecture models.
- Fewer supports – a flat cut face prints directly on the bed, overhangs disappear.
- Stronger parts – orient each piece so the layers follow the load.
- Multi-colour without AMS – print each piece in a different filament.
Cut STL in a slicer vs here
Bambu Studio, PrusaSlicer and Cura can cut, but the result lives inside a project. Here you get separate, watertight files you can share, sell or edit, the cut works on OBJ, 3MF and STEP too, and dowel holes plus matching dowels are created for you. Nothing is uploaded – the file never leaves your computer.
Frequently asked questions
Is cutting an STL online safe for my design?
Yes. The file is read and cut inside your browser tab; it is never uploaded to a server.
Does the cut keep the model watertight?
Yes. The cut faces are capped, so both pieces are closed solids that slice without errors.
Can I cut along an angle?
Cuts follow the X, Y or Z axis. Rotate the model first if you need an angled cut.
My model will not cut – what now?
It probably has holes or broken triangles. Fix it with the STL repair tool, then cut again.
Is it free?
Yes – up to 5 downloads a day are free, with no sign-up or watermark. Pro (free for 7 days) makes it unlimited.
Is my file uploaded?
No. The file is processed in your browser and never leaves your device.