Convert Spline to Polyline

There are a number of ways to convert splines to polylines. Here are some of them.

  • Flatten – if you have Express Tools installed, run the flatten command and select the splines. They will be converted to LWPOLYLINES regardless of the setting of PLINETYPE.
  • AutoCAD 2009 with Bonus Pack 1 or later – Spline to Polyline is included in the PEDIT command.
  • SPL2PL.VLX – This is a free tool from After you download it, drag and drop the .VLX file into the AutoCAD editor, then run the command SPL2PL. This tool will create a POLYLINE or LWPOLYLINE depending on the setting of the system variable PLINETYPE.
  • WMFOUT/WMFIN – Run the WMFOUT command, enter a filename, then select the splines. Now erase the spline, and then run the WMFIN command. Use the upper left corner of the viewport as the insertion point, and then scale it 2X. The resulting entity is a POLYLINE.
  • Save As R12DXF – If you save a drawing as R12 DXF format, all splines will be converted to POLYLINE entities.