Laser File Check

DXF checker for laser and CNC cutting

Check a DXF before it goes to a laser, CNC router, plasma or waterjet: units, open contours, duplicates, splines, hatches, blocks and 3D data.

Drop your SVG or DXF hereFrom Inkscape, Illustrator, Affinity, Fusion, LibreCAD and more · up to 30 MB

Checked entirely in your browser. Your file is never uploaded.

Machine and material (optional)

Only used to compare against your file. Leave blank to skip those checks.

What the DXF check looks at

  • Units: reads the drawing's unit setting and warns when it's missing, so the part doesn't import 25.4 times too big or small.
  • Open contours: connects lines, arcs and polylines end to end and reports chains that don't close. See the open polyline guide.
  • Duplicates: identical entities on top of each other, including lines drawn in reverse.
  • Entities that often fail to import: splines, hatches, dimensions, text, images, 3D solids and regions.
  • Blocks: block inserts are expanded with their position, scale and rotation, and nested blocks are reported.
  • 3D data: non-zero Z values and entities drawn on a tilted plane.
  • Size: overall extents, tiny features, and fit on your bed or material if you enter them.

Cleaning up a DXF

  • AutoCAD: OVERKILL removes duplicate and overlapping geometry, JOIN or PEDIT joins lines into polylines, and FLATTEN (an Express Tool, not available in AutoCAD LT) sets Z to zero.
  • Fusion: export the sketch with Save As DXF from a sketch on a flat plane, rather than exporting a projected 3D face.
  • LightBurn: after import, Edit → Delete Duplicates and Edit → Auto-join selected shapes handle many duplicate and gap problems.

Questions

My DXF has no units. What size will it import at?

It depends on the software: many assume millimeters, some inches, and some ask. The check shows the size under the assumption it made; change “If the file has no units” if that's wrong, and set the units in your CAD export settings.

Why are splines a problem?

Some laser and CNC programs don't import SPLINE entities at all, or turn them into rough line segments. Converting splines to polylines or arcs before export avoids surprises.

What does non-zero Z mean?

Some points have a height. For 2D cutting that's usually an accident from a 3D model or a moved sketch. Some software ignores Z, but some projects the geometry or rejects the file. Flatten the drawing before export.

Does it read binary DXF or DWG?

No. It reads ASCII DXF, which is what most programs export by default. Save as ASCII DXF, or export DXF from your DWG in your CAD program.