DXF vs DWG
DWG is AutoCAD's native, unpublished binary format; other programs rely on reverse-engineered libraries, so compatibility problems are common. DXF(Drawing Exchange Format) is the openly documented exchange format: mostly plain text, repeating “group code line + value line”. Nearly every tool — KiCad, Altium, Fusion, SolidWorks, laser cutters, CNC software — reads and writes it, which makes it the safest way to send a board outline to a fabricator.
Versions, encoding and units
R12 (AC1009) is the simplest and most compatible. 2000/2004 (AC1015/AC1018) add lightweight polylines and store text in the PC's code page. From 2007 (AC1021) text is UTF-8. Coordinates carry no unit: $INSUNITS(4 = mm, 1 = inch) says what they mean, but many programs leave it empty — a 100 × 80 outline is a small board in mm and 2.5 m in inches. The info panel shows the unit and mm-converted size; check it before sending. There is no “mil” unit in DXF, so export in mm.
Exporting a PCB outline
- AutoCAD — SAVEAS → “AutoCAD R12/LT2 DXF” or “2000 DXF”; set UNITS to millimeters first.
- KiCad — PCB Editor → File → Export → DXF (or Plot → DXF), Edge.Cuts layer only, mm.
- Altium Designer — File → Export → DXF/DWG, the mechanical/board-outline layer only, mm.
- Fusion 360 — right-click the sketch → Save as DXF; choose the origin beforehand.
What we check in an outline DXF
- A closed outline with no gaps or overlapping segments.
- Millimeter units and a sensible origin (bottom-left corner).
- Separate layers for outline, cutouts, slots and annotations — no text on the outline layer.
- 2D only, no stray Z values.
- Inside corners come out rounded by the router bit radius — tell us if you need sharp corners.
- Draw slots and cutouts as closed shapes and note whether they are plated.
Privacy
The viewer uses the open-source dxf-viewer library (MPL-2.0) and WebGL to render on your device. The drawing, its name and coordinates are never transmitted. The only outbound request is the font download when Show text is on; the site counts tool usage anonymously.