STL to SVG converter

To convert an STL to SVG, you flatten it. An STL is a 3D mesh and an SVG is a flat drawing, so you either trace the model's outline from one side or cut it with a plane and keep the cross-section. Drop the STL in the converter above, pick Outline, Slice or Layers, and download an SVG or DXF at true size in millimetres.

Outline, slice or layers

The outline is traced from a fine raster, accurate to about 0.05 mm at the standard detail; the panel shows the figure for your model. Slices are exact: every triangle the plane crosses adds one segment, and the segments are joined into closed loops.

Making a stacked model

1. Measure your sheet with calipers and enter that thickness. Nominal 3 mm plywood is often a little thinner, and the error adds up over many layers.
2. Set the size. Stack sets the finished height; Width and Height scale the footprint.
3. Enter your sheet or bed size and keep the layer numbers on. Parts are packed by their bounding box with the spacing you choose.
4. Cut, then stack from layer 1 at the bottom, lining each part up with the outline of the one below.

Each layer is cut at its own mid-height, and the layer count is rounded to the nearest whole layer, so the stack can differ from the model by up to half a layer. Choose File per layer when you want every layer in the model's own footprint: the files then line up with each other. If parts must slot together rather than stack, size them with the laser kerf calculator.

Getting the size right in LightBurn and Glowforge

The SVG states its width and height in millimetres, with a viewBox in the same units, so one unit is one millimetre.

• LightBurn has an SVG import setting under Settings, Import / Export: 96 DPI, Inkscape's default, or 72 DPI, Illustrator's default. Its docs say to try the other option if an SVG imports at the wrong scale. LightBurn matches imported colours to its palette, so the red cut lines and the blue layer numbers land on separate layers.
• Glowforge turns strokes into cuts and fills into engraves, and ignores stroke thickness, according to its support pages. Use Cut lines to cut and Filled to engrave. Text in an SVG must be converted to paths first; the layer numbers here are already drawn as strokes, so nothing goes missing.

Whatever you use, measure one part on screen before you cut.

STL to DXF for CAD and CNC

Switch the format to DXF for an AutoCAD R12 file in millimetres with closed polylines, the version CAD and CAM programs read most widely. Stacked layers get one DXF layer per slice and a LABELS layer for the numbers. LightBurn can detect the units when a DXF includes them, as this one does; otherwise you set them in its DXF import settings. Glowforge accepts DXF on its Premium plan. To go the other way, the SVG to DXF converter handles existing drawings.

Other ways to do it

• Autodesk Fusion: insert the mesh, then on the Mesh tab choose Create, Create Mesh Section Sketch and pick a plane. Edit the sketch and use Fit Curves To Mesh Section for real curves, then right-click the sketch in the Browser and choose Export DXF.
• Blender: in Edit Mode, Mesh, Bisect cuts a mesh with a plane. For an SVG, convert the object with Object, Convert, Grease Pencil, then use File, Export, Grease Pencil as SVG, which exports what the largest 3D viewport shows. DXF export needs the Export Autocad DXF Format extension.
• Inkscape cannot open STL files. It is useful once you have the SVG, for editing the outline.
• Slicer for Fusion 360, Autodesk's old app for stacked slices, is no longer listed on the Autodesk Marketplace (checked October 2026).

If the mesh is broken, fix it first with the STL repair tool, and check the model in the online STL viewer. To turn a drawing back into a 3D part, use the SVG to STL converter.