How to Import DXF Into LightBurn

LightBurn is one of the most popular laser programs in the world. It works with diode lasers, CO2 lasers and fiber lasers from many brands. And it reads DXF files well, which makes DXF one of the best formats to feed it.

This guide shows how to import a DXF into LightBurn, fix scale and color problems, clean up the lines and set your cut and engrave layers. It ends with a checklist you can use before every job.

Why use DXF in LightBurn?

LightBurn opens many formats, including SVG, AI, PDF and images. DXF stands out for precision. CAD programs export DXF with exact sizes, perfect circles and accurate arcs. If you are cutting parts that must fit together, such as boxes, brackets or panels, DXF is a great choice. Learn more about the format in what is a DXF file.

Step 1: Check the DXF before importing

Open the file in our free online DXF viewer first. It runs in your browser and does not upload anything. This gives you a baseline to compare with what LightBurn shows.

• Measure the overall width and height with the ruler tool.
• Note the units shown in the status bar, if any.
• Open the layers panel and note which layers hold cut lines, engrave lines and notes.
• Press F to fit. If the design is tiny in a corner, there is a stray object.

Step 2: Import the DXF into LightBurn

1. Open LightBurn.
2. Choose File, then Import. On Windows the shortcut is Ctrl and I. On Mac, Command and I.
3. Pick your DXF file and click Open.

You can also drag the DXF straight onto the LightBurn workspace. The design appears selected, ready to move.

Step 3: Check the size

Select the whole design and look at the width and height boxes at the top. Compare them with the numbers from the viewer.

• If it matches, great. Move on.
• If it is about 25.4 times too small or too big, it is an inch and millimeter mix up. Type the correct width with the lock icon on to keep proportions.
• If it is off by another amount, check the designer’s notes for the intended size.

LightBurn has import settings for DXF files in its settings window. If you often get wrong sizes from the same source, check those settings once and adjust them.

Step 4: Understand the colors and layers

LightBurn uses colors as layers. Each color in the Cuts and Layers panel has its own settings, like speed, power and mode. When you import a DXF, LightBurn assigns colors based on the colors in the DXF.

If the designer used different DXF colors for cut and engrave lines, you will see several layers in LightBurn. That is helpful. If everything came in as one color, you can split it yourself.

1. Select the lines you want to engrave or score.
2. Click a different color in the color palette at the bottom.
3. Those lines move to a new layer.

Now you can set the cut layer to Line mode with high power, and the score layer to Line mode with low power, or a Fill layer for engraving areas.

Step 5: Clean up the lines

DXF files from CAD and online sources often have small problems that cause bad cuts. LightBurn has tools to fix them.

Delete duplicate lines

Doubled lines make the laser cut the same path twice, which burns the edge and wastes time. Select everything and use Edit, then Delete Duplicates.

Join lines into closed shapes

DXF exports sometimes split a shape into many separate lines. Select them and use Edit, then Auto-Join Selected Shapes. This joins lines that meet end to end.

Close small gaps

If a shape still is not closed, use Edit, then Close Path with Tolerance. Set a small tolerance, such as 0.1 mm, so it only closes tiny gaps.

Check for open shapes

Open shapes cannot be filled, and they may cut in odd orders. Use the selection tools in the Edit menu to select open shapes and see which ones need work.

Remove stray objects

Delete anything outside your design, such as dots, notes or borders.

Step 6: Set your cut settings

Every machine and material needs its own settings. Use your laser maker’s guide or a material test card as a starting point. In the layer settings, set:

• Mode: Line for cutting and scoring, Fill for engraving areas.
• Speed and power: based on your material test.
• Number of passes: more passes for thicker material.
• Kerf offset: optional, for parts that must fit tightly.

Use the Preview window to see the job path and an estimated time. Check that inner shapes cut before outer shapes. LightBurn’s optimization settings can handle this for you.

A real example: cutting a finger joint box

Say you make a box with a free online generator, sized for 3 mm plywood, and download it as DXF. Here is the full workflow.

1. Open the DXF in the viewer. You see six panels with finger joints. You measure the front panel at 120 mm wide, just as you set it.
2. Import it into LightBurn. The size matches.
3. Select all and run Delete Duplicates. LightBurn removes a few doubled edges where panels share a line.
4. Run Auto-Join. The finger joint outlines become closed shapes.
5. Put all lines on one cut layer, with settings from your 3 mm plywood test.
6. Cut a single small panel first as a test. Check that the fingers fit their slots.
7. If the joints are loose, add a small kerf offset in the layer settings, such as 0.05 to 0.1 mm, and test again.
8. Cut the full box.

This test first approach costs one small offcut and saves a full sheet.

Exporting DXF from other programs for LightBurn

If you make your own designs, how you export matters.

• From Fusion: right-click a sketch and choose Save as DXF. Each sketch becomes one clean file.
• From Inkscape: save as a desktop cutting plotter DXF. Convert text to paths first. See our Inkscape guide.
• From Illustrator: export as DXF and choose a version like 2000. Outline your text before export.
• From AutoCAD: keep only the cut geometry, use clear layer colors, and save as DXF 2000.

Common LightBurn DXF problems

The import fails or nothing appears

The DXF may be binary, too new or damaged. Save it again as an ASCII DXF, version 2000 or R12. See DXF file not opening.

Text is missing

CAD text in DXF files may not import as you expect. Ask the designer to convert text to outlines before export. Or add the text again in LightBurn.

Curves look like straight segments

Some programs export curves as many short lines. The cut will still work, but it may be slower. If smoothness matters, ask for a better export.

The design is in the wrong place

LightBurn keeps the DXF coordinates. If the design was drawn far from 0,0, it may import off the bed. Select it and move it, or use the alignment tools to center it.

Everything is one color

The DXF had no colors, or LightBurn was set to ignore them. Assign colors by hand as shown above.

Pre-cut checklist

1. Size matches the intended size.
2. No duplicate lines.
3. All cut shapes are closed.
4. No stray objects outside the design.
5. Cut and engrave layers have the right settings.
6. Inner cuts run before outer cuts.
7. Material is safe for laser cutting.
8. Focus is set and air assist is on.

Save your work as a LightBurn file

Once your DXF is cleaned up and your layer settings work, save the project as a LightBurn file. It keeps the joined shapes, colors and settings together. Next time you cut the same part, open that file instead of the DXF. You skip the cleanup and get the same result every time. Keep the original DXF too, in case you need to change the design later.

Safety reminder

Never cut PVC or vinyl on a laser. It releases chlorine gas, which harms you and your machine. Never leave a running laser unattended, and keep a fire extinguisher nearby.

Frequently asked questions

Does LightBurn support DXF files?

Yes. Use File, then Import, or drag the file into the workspace.

Why is my DXF the wrong size in LightBurn?

The drawing units and LightBurn’s settings do not match. Scale by 25.4 for inch to millimeter mix ups, or check the DXF import settings.

Is DXF or SVG better for LightBurn?

Both work. DXF is often more precise for mechanical parts. SVG often keeps colors from design apps.

Where can I find DXF files for laser cutting?

See our guide to free DXF files.

Can I import DXF files from Fusion 360?

Yes. Export a sketch as DXF in Fusion, then import it. See our Fusion DXF guide.

Check your DXF first

Before you import, open your file in our free DXF viewer. Measure it, check the layers and look for stray objects. Then import it into LightBurn and cut with confidence.