How to cut an STL in half (every slicer, plus the browser)
Quick answer: in Bambu Studio, OrcaSlicer, PrusaSlicer and Creality Print, select the model and press C. Drag the plane or type a height, keep both parts, add a Plug or Dowel connector if you want alignment, then Perform cut. Cura cannot cut a continuous mesh. In Blender, use Mesh ‣ Bisect with Fill. In the browser, open the model in splicestl, choose N pieces, set the axis you want to 2, and Split. The cut lands at the model's midpoint, or at the lowest-cost seam nearby if you turn on seam-aware placement. Both halves are capped and verified watertight, and the zip holds pegs and an assembly sheet.
- Cutting in half is the one case where a slicer's single-plane Cut tool is enough; the moment you need two or more cuts, or the halves must fit a specific bed, a splitter saves the arithmetic.
- Whatever cuts it, check the cut face is closed (capped) before slicing: an open half prints as a hollow shell.
Bambu Studio, OrcaSlicer, PrusaSlicer
The three share one Cut tool (Orca forked Bambu Studio, which forked PrusaSlicer). Select the object, press C or click Cut in the left toolbar. A plane appears at the model's centre; drag it with the arrow, rotate it with the ring, or type the height. Keep both Upper and Lower parts, choose whether each is placed on the bed or flipped, and, in Planar mode, optionally add connectors: Plug (a peg on one half, socket on the other), Dowel (sockets both sides, you print or buy the pin) or Snap. Switch to Dovetail mode for a sliding joint instead. Click Perform cut; the two halves become separate objects you can arrange and export. One plane per operation; the slicer does not check whether the halves fit the bed.
Creality Print
Creality Print 5.0 and later is built on OrcaSlicer, so the Cut tool is the same: select, press C, set the plane (rotate it to snap to an axis, or hold Shift and drag to draw a freehand plane), Planar or Dovetail, perform cut. See the Creality Print guide for the details and the version differences.
Cura
Cura has no cut tool. "Split model into parts" (from the Mesh Tools plugin) only separates meshes that are already disconnected shells — it cannot cut a continuous model. The usual workaround, sinking the model below the bed and slicing twice, produces two prints but no files and no cap, so you cannot add connectors. Cut the STL elsewhere and import the halves; the Cura guide walks through it.
Blender
Edit Mode, select all, Mesh ‣ Bisect, type the plane point and normal, tick Fill and Clear Outer; undo and repeat with Clear Inner for the other half; export each with Selection Only. Without Fill the halves are open. The Blender guide covers numeric placement, peg sockets with a Boolean and the manifold check.
In the browser (no install)
- Open splicestl and drop the STL, 3MF or OBJ on the page. Nothing is uploaded; it runs in the tab.
- In step 2 (Your printer) set Cut strategy to N pieces and set the axis you want cut to 2 (the other two stay at 1). The orange plane shows the cut; drag its handle to move it, and the label reads the height and the seam cost.
- Pick a connector in step 3 — pegs is the default; None for a plain cut. The split runs by itself; Split mesh reruns it after a change.
- Download: two capped, watertight halves lying flat on their cut faces, the pegs, a README and an assembly sheet.
Prefer the cut where the model is thinnest, or away from a face or a logo? Turn on seam-aware placement and Shift+click any spot the seam must avoid; the cut slides to the lowest-cost position within reach.
Which to use
| You want | Use |
|---|---|
| Quick halves inside the slicer you already have open | Bambu Studio / Orca / Prusa / Creality Print Cut tool (C) |
| Halves that fit a specific printer, with connectors and a watertight guarantee | splicestl |
| A cut at an angle or along a feature, then further editing | Blender Bisect |
| You are in Cura | Cut elsewhere, import two files |
Frequently asked questions
How do I cut an STL in half in Bambu Studio?
Select the model, press C, drag the plane or type the height, keep both parts, optionally add a Plug or Dowel connector, and click Perform cut. The halves become two objects you can arrange and export.
Can Cura cut an STL in half?
No. Cura's "Split model into parts" (Mesh Tools plugin) only separates already-disconnected shells. Cut the file in a slicer with a Cut tool, in Blender, or in the browser with splicestl, then import the two halves.
How do I cut an STL in half online without installing anything?
Open splicestl in the browser, drop the file, choose N pieces and set one axis to 2, pick pegs or no joinery, click Split, download the zip. The file never leaves your computer; the halves are capped and verified watertight.
Why is my cut half hollow when sliced?
The cut face was not capped: Blender's Bisect without Fill, or a tool that left an open edge loop. Re-cut with Fill, or run the half through a repair that closes holes; splicestl caps every cut and checks the result before export.
Should the cut go through the middle?
Only if the middle is the best place. Put the seam where the cross-section is small, across a flat band or a natural edge rather than a face or a detail, and where both halves can lie on the cut face to print without supports. Seam-aware placement in splicestl scores candidate positions for exactly that.
Sources
- Bambu Lab wiki, Bambu Studio — Cut tool — Planar and Dovetail modes, Plug / Dowel / Snap connectors, plane controls. Read 13 Oct 2026.
- Prusa Knowledge Base, Cut tool. Read 13 Oct 2026.
- OrcaSlicer wiki, Cutting tool. Read 13 Oct 2026.
- Blender 4.2 LTS Manual, Bisect. Read 13 Oct 2026.
- CrealityOfficial/CrealityPrint on GitHub, issue #428 — the Cut tool's planar and dovetail modes, plane rotation and Shift+drag in 6.2. Read 13 Oct 2026.
What changed — 13 October 2026: first published.