DWG vs DXF: what differs and which one to send
Both are drawing files, but they are not the same thing. One is binary, the other readable text — and that difference sometimes saves a project.
The same drawing can arrive in two different containers. DWG is AutoCAD's native format and is binary — open it in a text editor and you get noise. DXF is the interchange format Autodesk publishes, and it is plain text; open it and you see group codes and values listed line by line.
What actually differs
| DWG | DXF | |
|---|---|---|
| File size | Small | Typically 3–5× larger |
| Readability | Binary, opaque | Plain text, inspectable |
| Software support | Autodesk-centric | Almost every CAD package |
| Damage tolerance | One bad byte can take the whole file down | The broken part can be skipped and the rest recovered |
| Version sensitivity | High | More forgiving |
Why DXF still matters
Because DXF is text, it is both portable and repairable. A damaged DWG usually will not open at all; with DXF you can skip the bad section and read the rest. For the same reason most non-CAD systems — laser cutters, CNC, survey equipment — ask for DXF.
Group codes
A DXF is made of number-value pairs called group codes: 10 is an X coordinate, 20 a Y coordinate, 8 a layer name. That simplicity is the format's strength and also its trap, because some codes change meaning with context. Code 98, for instance, is a hatch seed point in one place and something else entirely in another. A reader that does not track the context invents lines that were never in the drawing.
Which one to send
- Same team, same software: DWG. Smaller, and everything stays where it belongs.
- A subcontractor on different software: DXF. Compatibility problems drop to a minimum.
- A fabricator or CNC shop: DXF, preferably with the layers cleaned up.
- Someone who only needs to look: neither — send a true-scale PDF. Here is how.
Try it with your own drawing
Drop a DWG or DXF and take away a true-scale vector PDF. Nothing to install.
Related reading
How to convert a DWG file to PDF properly
Turning a drawing into a PDF is easy. Doing it without losing the scale, the colours and the hatches is not. Step by step.
Opening a DWG file without AutoCAD
You have no licence but you need to read the drawing. The options, what each is good for, and where each falls short.
1:50, 1:100 — how to export a PDF at true scale
A scaled export is one you can measure with a ruler. What scale means, which to use when, and why it sometimes comes out wrong.