SVG vs DXF for Laser Cutting: Which File Format to Use

You downloaded a design, dragged it into your software, and the reindeer is now the size of a postage stamp. Or a house. Or the lines are the wrong color and it all cut as one layer. Nine times out of ten, the culprit is the file format, or more exactly how the format stores size and color.

SVG vs DXF for laser cutting is not a fight with a winner, because each was built for a different job. SVG comes from the web and graphic design world; DXF comes from CAD and engineering. Once you know what each one remembers and what it forgets, picking is easy.

SVG vs DXF for laser cutting: the real differences

An SVG is basically a drawing with colors. A DXF is basically a technical drawing with layers. Both are vectors, meaning lines and curves that cut cleanly at any size, unlike a JPG or PNG.

Which software opens which

Here is what the common programs accept. Always confirm against the app's current documentation, because support changes between versions.

See the dedicated answers in Can Glowforge Open DXF Files? and What File Formats Does LightBurn Support?.

How sizes go wrong

This is the part that trips everyone.

• SVG can declare its size in millimetres, inches or pixels. Pixels depend on a resolution assumption (commonly 96 DPI in browsers and Inkscape, 72 in older Illustrator exports). If the app assumes a different one, your design scales by about 25 percent or more.
• DXF usually has no on-screen unit. Software must decide whether a "90" means 90 mm or 90 inches. Most laser software asks, or lets you set a default.

Both of those problems are covered in Why Is My SVG the Wrong Size in LightBurn? and What Units Should a DXF File Use?.

Common mistake: Trusting the size on screen. Always measure a distance in your software against the real dimensions on the product page. For the reindeer ornament it should read 90 × 124 mm, and your preview should match.

Colors, layers and what they do on the laser

Laser software decides what to do with a line mainly by its color (LightBurn, RDWorks) or its layer (some CAD workflows). That is the whole reason files are organised the way they are.

DXF World files follow exactly this convention: SVG with a red CUT hairline and black ENGRAVE fill; DXF with layers CUT and ENGRAVE. Read more about the hairline in What Is a Hairline Stroke in a Laser File? and about layer logic in Cut, Engrave and Score Layers Explained.

Pro tip: If you pick DXF and your engrave areas come in as outlines instead of filled shapes, that is normal. DXF has no real fill concept in most laser apps. Set the layer to fill in the software.

When to choose SVG

• You use Glowforge, or your design has artwork and colors
• You are drawing in Inkscape or Illustrator
• You want shapes with engraved fills
• The file might be shared with people who do not own CAD software

When to choose DXF

• Your workflow starts in CAD or box generators
• You need millimetre precision for joints and tabs, such as our finger joint box generator, which exports both SVG and DXF
• You use RDWorks or older CO2 controllers that love DXF
• The part is purely lines and arcs

Problems you will actually meet

Practical rule of thumb

If you do not know which to use, download both when the site offers them. We do, for every file. Open the SVG first, measure the dimensions, and keep the DXF for when something needs a CAD edit. Then test a cut on scrap.

A quick test to run on any file

Before you trust a file, spend 60 seconds on this checklist. It catches nearly every format problem before the laser ever fires.

1. Import it into your software without scaling.
2. Measure one known dimension (for example the 90 mm width of the reindeer).
3. Look at the layers or colors and confirm cut and engrave are separate.
4. Zoom way in on corners to see whether lines are closed or leave gaps.
5. Run Frame or a preview to see the toolpath order and the time estimate.

If the preview time looks absurd (say 40 minutes for a tiny ornament), you probably have duplicate lines stacked on top of each other, which cut twice. Our time estimates, for example 1 min 48 s on a 10 W diode for the reindeer, give you a handy reality check.

Converting between the two

You can move between formats, but be careful what you lose.

Pro tip: After any conversion, measure again and check for duplicates. Conversion is where file size bugs are born.

What about AI, PDF and PNG?

You will meet other formats too. AI and PDF files can contain real vectors and often open fine in LightBurn, but they carry baggage such as artboard sizes, embedded fonts and effects that do not translate to laser paths. PNG and JPG are pictures made of pixels: great for engraving a photo, useless for clean cutting lines until you trace them into vectors (see How to Turn an Image into a Laser Cut File). If you have a choice, a plain SVG or DXF with simple closed shapes will behave better than anything fancier.

Another small thing: fonts. If a design includes text, convert it to outlines or paths before you export. Otherwise the file may open on another computer with a different font, or the laser software may not understand it at all. Nothing is sadder than a wedding sign that comes out in a default typeface.

Next step

Open any file in the free library in both formats and compare them in your own software. Check the size, check the layers, and note which version behaves best for your machine. After that, read How to Prepare an SVG for Laser Cutting to avoid the usual traps.