Our STL & 3MF splitting features

Five ways to cut a model

Planar, Area, Dovetail, and Smart Detach work on both STL and 3MF meshes. Separate by Color needs a painted 3MF, because STL files carry no color information. Whichever tool you use, the parts export as STL or 3MF for your slicer.

Planar Cut

STL and 3MF

Slice clean through the model with a flat plane. This is the classic split when you need a straight, predictable seam.

Position a cutting plane anywhere on an STL or 3MF, preview both sides, and commit. The two halves land in the parts list with flat mating faces, ready for dowels, plugs, or magnets. It is the fastest way to make an oversized model fit your build volume or to split a print for cleaner layer lines.

Best for models taller or wider than your printer, two-piece splits, straight glue seams.

Planar Cut guide

Area Cut

STL and 3MF

Cut only inside a rectangle or circle on the plane. Reshape a region without splitting the entire mesh.

Area Cut is a planar cut with a window. Draw a rectangle or circle on the plane and only the geometry inside it is separated; the rest of the mesh stays in one piece. Use it to lift a hatch, panel, or insert off a surface, or to isolate a spot for a connector without a full bipartition.

Best for removable panels, local inserts, surgical edits where a full plane would cut too much.

Area Cut guide

Dovetail Cut

STL and 3MF

Interlocking teeth that slide together and lock. The seam helps parts self-align.

Dovetail Cut turns a split into a joint. Instead of two smooth faces, the seam gets interlocking teeth that guide assembly and resist shear, so large props and cosplay pieces line up the same way every time. Tooth size is adjustable to match your printer’s tolerance, and the joint is generated for you rather than modeled in CAD.

Best for large props, helmets, and structural parts that must self-align before glue.

Dovetail Cut guide

Smart Detach

STL and 3MF

Click a feature and peel a whole piece off cleanly. Built for parts that should print separately.

Smart Detach follows the shape of the model instead of a plane. Click an arm, horn, chimney, or accessory and the selection floods across that feature up to its natural boundary; a threshold lets you tighten or widen the flood. The clicked piece becomes its own part, so you can print it flat with fewer supports or make a fragile detail replaceable.

Best for protruding details, accessories, and anything that prints better on its own.

Smart Detach guide

Separate by ColorBeta

Painted 3MF only

Import a painted 3MF, click a color, and detach that region. Useful for multi-material workflows without redoing paint in CAD.

Open a 3MF you painted in Bambu Studio, Orca Slicer, or PrusaSlicer and the colors load with the mesh. Click a paint region and Multipart3D detaches it as a separate part, with colors preserved on export where the format supports it. That makes multi-color and multi-material prints possible without repainting the mesh, and separate parts can be printed one color at a time on a single-extruder printer.

Best for painted 3MF files, filament swaps, armor-versus-skin splits on miniatures and busts.

Separate by Color guide

Connectors, available after every cut

Connectors are not a separate cutting method. Once a model is split with any of the five tools above, you can click the mating faces to add alignment and locking hardware before you export.

Connectors & joints

After any cut

Split parts are only half the job. Connectors help them go back together the way you intended.

After any cut, click the mating face to place plug, dowel, snap-fit, pin-hole, or magnet connectors. Plugs and dowels come in circle, square, hex, and triangle cross-sections; magnet pockets use presets such as 6×3 and 8×2 mm. Tolerance presets for FDM and resin (tight, standard, loose) mean the parts dry-fit before glue instead of after sanding.

Best for aligning glued halves, remountable accessories, dry-fit assemblies.

Connectors & joints guide

• Plug
• Dowel
• Snap-fit
• Pin hole
• Magnet

Which cut should I use?

Most models only need one of these. Start from the problem you are trying to solve, not from the tool.

The model is too big for my build plate

Use Planar Cut. A flat plane gives the most predictable seam and the largest flat faces for connectors. Add a dovetail instead when the halves must self-align.

I want the two halves to lock together, not just touch

Use Dovetail Cut. Interlocking teeth carry the alignment for you, which matters on large props, helmets, and anything that ships or travels in pieces.

I only need to remove or reshape one region of a surface

Use Area Cut. The rectangular or circular window limits the cut to the area you choose, so the rest of the mesh stays whole.

An arm, horn, or accessory should print as its own part

Use Smart Detach. Click the feature and the selection follows its natural boundary. No plane to position, and the piece can be laid flat for fewer supports.

I painted the model in my slicer and want one part per color

Use Separate by Color. Separate by Color turns painted 3MF regions into meshes so you can print colors or materials as separate parts.

The parts are cut but I need them to align and stay together

Use Connectors & joints. Plugs, dowels, snap-fits, pin holes, and magnet pockets are placed on the cut face with FDM- and resin-friendly tolerances.

A typical split, start to finish

Whatever the cut, the workflow is the same and stays inside one browser tab.

1. Drop an STL or 3MF onto the page. The mesh is read locally; nothing is uploaded.
2. Check the build-volume overlay to see whether the model, or its future parts, fit your printer.
3. Pick a cut (planar, area, dovetail, smart detach, or separate by color), preview the result, and commit.
4. Move parts apart to inspect the seam, then drop them to the bed so each one has a printable base.
5. Add connectors to the mating faces if the parts need to align or remount.
6. Export each part as STL or 3MF and slice them in Bambu Studio, Orca Slicer, PrusaSlicer, or Cura.

Also included

Smaller capabilities that make the cuts above practical for real prints.

STL and 3MF import and export

Load classic STL meshes or 3MF files, including painted 3MF from Bambu Studio, Orca Slicer, and PrusaSlicer. Export parts in either format.

Build-volume overlay

A printer-sized box in the viewport so you can judge whether parts will fit before and after a cut.

Parts list and per-part export

Every cut or detached piece shows up as its own part. Export one part, or all of them, in one click.

Move, inspect, and drop to bed

Pull halves apart to inspect the seam, then place each part flat on the bed so it is ready to slice.

Tolerance presets

Connector clearances for FDM and resin (tight, standard, loose) or a custom value for your printer and filament.

Private by design

No account, no upload, no server-side processing. Files stay in the browser tab you opened, so client and commercial work is safe to cut here.

Questions about the tools