Download both if you are unsure — they describe the same millimetre geometry, produced from one shared normalisation, so there is no quality difference to weigh up.
The only real question is which importer you are feeding. Match the format to the software and the decision takes five seconds.
They are the same geometry
The final contour is normalised exactly once, before either exporter runs, so both files start from an identical shape with its bottom-left corner at the origin.
SVG then flips Y, because SVG's Y axis points down. A vertex at internal (10, 4) in a part of height H becomes (10, H − 4) in the SVG and stays (10, 4) in the DXF. Importers that understand each format put the part back in the same physical place.
That single shared normalisation is deliberate: if each exporter normalised on its own, the two files could drift apart by a rounding digit and nobody would notice until a part came off the machine.
When to pick SVG
SVG is the right default for LightBurn, Inkscape, and most laser-first workflows, and it is the only format you can paste straight back into a drawing app.
It must carry width and height in millimetres plus a viewBox of 0 0 w h with the same numbers. Omit either and importers fall back to 96 units per inch, which is where the familiar 3.7795 scale error comes from.
Reliefs are written as A commands — true circular arcs — rather than cubic approximations. Bézier curves survive the round trip visually but tessellate badly in CAM, and the tessellation error lands exactly on the fit surface you care about.
When to pick DXF
DXF R12, identified as AC1009 in the header, is the right default for Carbide Create, Fusion's DXF import, and a great deal of older Windows CAM still running in shops.
The file contains LINE and ARC entities only. Arcs are stored as a centre, a radius, and start and end angles measured counter-clockwise, which is a lossless way to describe the relief.
There is no unit field worth trusting in R12, so the import dialog that asks you is not optional — pick millimetres. Beyond that, DXF is the more predictable of the two formats because there is no viewport concept to misread.
Things that go wrong
Do not convert SVG to DXF through an online converter. Those tools routinely explode arcs into polylines, apply a 96 dpi assumption, and occasionally mirror Y twice. The two buttons on this page share one contour and one normalisation; a converter adds a third opinion.
If a CAM tool only accepts polylines it will tessellate the DXF ARC on import. That is still better than a Bézier from a drawing app, because the tessellation starts from a true circle of radius R rather than from an approximation of one.
File size is negligible either way, so it is never a reason to choose. Match the importer: LightBurn takes SVG, Carbide Create takes DXF, Easel takes SVG, and for anything unfamiliar try DXF first.
Neither file is G-code
Both downloads are part geometry. Feed rates, plunge rates, ramps, tabs, and depth per pass all live in CAM, and this site will never write them.
That also means both files are the finished pocket contour rather than a cutter-centre toolpath. Import, set the same bit diameter, and let CAM do the offset once.