What is a .dxf file?
Drawing Exchange Format · 3D model · Autodesk · 1982
DXF is Autodesk's open interchange format for CAD drawings. It carries the same vector geometry as DWG but in a documented, text-friendly form, so it is the reliable way to move designs between different CAD programs.
What is a .dxf file used for?
DXF was created so CAD data could move between AutoCAD and other software. Its structure is published, and the ASCII variant is even human readable.
It preserves layers, lines, arcs, text and other 2D and 3D entities, making it the common ground when two people use different CAD tools.
It is also widely accepted by laser cutters, CNC machines and vector tools that need precise paths.
DXF comes in two flavours that hold the same geometry: a human-readable ASCII form you can open in a text editor, and a more compact binary form. Like DWG, it is versioned by AutoCAD release, so if an older program rejects a DXF, re-exporting it to an earlier version usually fixes it.
What opens a .dxf file?
The .dxf format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- AutoCAD
- LibreCAD
- Inkscape
- DWG TrueView
macOS
- LibreCAD
- AutoCAD
- Inkscape
Linux
- LibreCAD
- Inkscape
- FreeCAD
Web
- Online CAD and DXF viewers
Open a .dxf file step by step
- Confirm the file really is a .dxf. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with AutoCAD or LibreCAD.
- On Mac, use LibreCAD or AutoCAD.
- On Linux, try LibreCAD or Inkscape.
- Still stuck? Convert the .dxf to DWG, which opens more widely.
Why can't I open my .dxf file?
Almost always because no installed app understands DXF. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .dxf at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .dxf file
You can convert a .dxf file to DWG, SVG, PDF.
LibreCAD and QCAD open DXF directly and export to SVG or PDF. Going to SVG turns a dimensioned drawing into pure geometry, so the measurements stop being editable.
What is the .dxf file signature (magic bytes)?
A .dxf file may start with the hex bytes 30 0D 0A 53 45 43 54 49 4F 4E, which read as 0..SECTION in ASCII. Those bytes are a hint rather than a guarantee, so DXF cannot be identified by its header alone.
These are the documented signatures for DXF.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 30 0D 0A 53 45 43 54 49 4F 4E | 0 | 0..SECTION | text DXF often begins with a section marker |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .dxf file?
DXF is Autodesk's open interchange format for CAD drawings. It carries the same vector geometry as DWG but in a documented, text-friendly form, so it is the reliable way to move designs between different CAD programs.
Can I open a DXF in Illustrator or Inkscape?
Yes. Both import DXF as vector paths, which is handy for turning CAD drawings into artwork or cut files.
Why does my DXF open at the wrong size?
DXF does not always record its drawing units, so the importing program may guess millimetres for inches or vice versa. Check the unit setting when you import, or scale the drawing to match, especially before laser cutting or CNC.
Related formats
Sources
Details on this page were checked against authoritative references. How sources are ranked and what is deliberately left out is set out in the methodology.