Two things are worth knowing about Drawing Exchange Format before you try to open one. A DXF written by a non-Autodesk tool often drops the dimension and hatch entities.
| Written by | Autodesk Inc. |
| Signature | Section headers: 0 / SECTION / 2 / HEADER at offset 0 |
| Full name | Drawing Exchange Format |
| Extension | .dxf |
The structure, briefly
ASCII (or binary) group-code pairs: an integer group code followed by its value, organised into HEADER, CLASSES, TABLES, BLOCKS and ENTITIES sections.
Recognising the format
The format announces itself in plain text: Section headers: 0 / SECTION / 2 / HEADER near the start of the file. If that string is missing, whatever produced the file is not what the extension claims.
Someone sent us a .dxf file with a .tmp suffix on it last month; the header was the original all along and only the name had been changed. Renaming does not rewrite a header.
Programs that open it
Installed options: AutoCAD, Bentley MicroStation, LibreCAD (free), QCAD (free), Inkscape (import). None of them have to be the program that made the file: Universal Viewer reads it and writes nothing back.
Converting .dxf to something usable
The targets people actually ask for are .dwg, .pdf, .svg, .stl. Each one has its own page with the settings that matter: dxf → dwg, dxf → pdf, dxf → svg, dxf → stl
Asked often
What opens .dxf if I do not have Autodesk?
AutoCAD, Bentley MicroStation, LibreCAD (free). If nothing installed reads it, the viewer above does.
Can I convert .dxf without the original program?
For the targets listed above, yes. The container survives; what is lost is whatever the target format cannot hold.
Notes from the file library
Files of this kind are catalogued with the family named in the table above. The family groups them by what a file carries, not by the application that wrote it, which is why two extensions from the same application can sit in different families.
Two things decide whether a file can be opened on a machine that never had the application that made it: the header, which says what the container is, and the structure behind it, which says whether the contents can be read at all. The conversion guides listed on the page cover the targets that come up most often.
Format pages are rebuilt with each release of the toolset, and the review line at the bottom of the page is when an editor last checked the entry against a file. If a page disagrees with a file you have, send the first sixteen bytes and the build number to the support address and the entry is corrected in the next build.
Reviewed 2026-10-05 by M. Halvorsen.