DXF (Drawing Exchange Format) is an open CAD file format created by Autodesk in 1982 to enable data exchange between AutoCAD and other software. Unlike the proprietary DWG format, DXF uses a documented, text-based (or binary) structure that any CAD application can read and write. For surveyors, DXF is the most common format for delivering 2D drawings — site plans, cadastral boundaries, contour maps, feature surveys, and as-built drawings. If you’ve ever sent a survey drawing to a client, an architect, or an engineer, chances are it was a DXF.
I deliver DXF files on almost every project. It’s the universal exchange format for 2D survey deliverables, and understanding what’s inside one (and what can go wrong) will save you and your clients a lot of frustration.
DXF vs DWG
This is the first question everyone asks: what’s the difference between DXF and DWG?
| DXF | DWG | |
|---|---|---|
| Full name | Drawing Exchange Format | Drawing (proprietary) |
| Developer | Autodesk | Autodesk |
| First release | 1982 | 1982 |
| Format type | Open (documented specification) | Proprietary (reverse-engineered by others) |
| File structure | ASCII text or binary | Binary only |
| Readability | Human-readable (ASCII version) | Not human-readable |
| File size | Larger (especially ASCII) | Smaller (more efficient encoding) |
| Compatibility | Virtually universal | Best in Autodesk products |
| Feature support | Most CAD features | All AutoCAD features |
| Proxy objects | Not supported | Supported |
| Custom objects | Limited | Full support |
| Typical use | Data exchange between systems | Working files within AutoCAD |
In practice: You work in DWG (or your CAD software’s native format), and you export DXF for delivery and exchange. DXF is the PDF of the CAD world — it’s what you send when you want everyone to be able to open it.
There are some features that DXF doesn’t fully support — complex hatch patterns, some 3D solid types, proxy objects from AutoCAD verticals (Civil 3D surfaces, pipe networks), and OLE embedded objects. For survey drawings, which are predominantly 2D lines, arcs, text, and points, DXF handles everything you need.
What’s inside a DXF file
A DXF file is organised into sections. If you open an ASCII DXF in a text editor (which you can do — try it), you’ll see a structured but verbose format:
Sections
| Section | Contents |
|---|---|
| HEADER | Drawing settings — units, coordinate system, extents, version |
| CLASSES | Custom object class definitions (rarely relevant for survey DXF) |
| TABLES | Layer definitions, line types, text styles, dimension styles, viewports |
| BLOCKS | Block definitions (reusable symbol groups like survey markers, trees, manholes) |
| ENTITIES | The actual drawing geometry — lines, arcs, polylines, text, dimensions, points |
| OBJECTS | Non-graphical objects like dictionaries and layouts |
For surveyors, the two most important sections are TABLES (specifically layers) and ENTITIES (the geometry).
Common entity types in survey DXF files
| Entity | Description | Survey use |
|---|---|---|
| POINT | Single XYZ coordinate | Survey marks, spot heights |
| LINE | Straight line between two points | Boundary lines, building edges |
| ARC | Circular arc | Curved kerbs, road centrelines |
| POLYLINE / LWPOLYLINE | Connected sequence of line/arc segments | Property boundaries, contours, road edges |
| CIRCLE | Circle with centre and radius | Manholes, tree canopies |
| TEXT / MTEXT | Single-line or multi-line text | Labels, annotations, dimensions |
| INSERT | Block reference (places a defined block) | Survey markers, utility symbols |
| DIMENSION | Linear, angular, or radial dimension | Setback distances, lot widths |
| HATCH | Filled area pattern | Building footprints, water bodies |
| SPLINE | Smooth curve through control points | Natural features, creek lines |
| 3DFACE | Triangular or quadrilateral 3D surface | TIN surfaces (less common in exchange) |
| ATTRIB | Attribute attached to a block | Survey mark ID, RL value, description |
Layers
Layers are the organisational backbone of any survey DXF. Each entity is assigned to a layer, and layers are typically structured by feature type:
| Layer example | Content |
|---|---|
| BOUNDARY | Cadastral/property boundaries |
| CONTOUR-MAJOR | Major contour lines (e.g., 1 m interval) |
| CONTOUR-MINOR | Minor contour lines (e.g., 0.25 m interval) |
| BUILDING | Building outlines |
| ROAD | Road edges, centrelines |
| FENCE | Fence lines |
| TREE | Tree locations (typically blocks with canopy circle) |
| SERVICES-WATER | Water mains, hydrants |
| SERVICES-SEWER | Sewer mains, manholes |
| SERVICES-ELEC | Electrical cables, poles |
| TEXT | Labels and annotations |
| SURVEY-MARKS | Survey control marks |
| SPOT-HEIGHTS | Spot elevation points |
Layer naming conventions vary by organisation and jurisdiction. In Australia, many state governments publish layer standards for cadastral and infrastructure mapping. In the US, the National CAD Standard provides layer naming guidance. Always ask the client for their preferred layer structure before starting.
Common uses in surveying
Feature surveys / detail surveys
The most common survey DXF deliverable: a 2D plan showing all visible features on a site — buildings, fences, trees, kerbs, services, spot heights, and contours. This forms the base information for architects and engineers designing on the site.
Cadastral / boundary surveys
Property boundary plans showing lot boundaries, easements, setbacks, dimensions, bearings, and areas. These are often lodged with government authorities and must comply with specific drafting standards.
Contour maps
Contour lines interpolated from survey data (total station, GNSS, or LiDAR-derived). Delivered as polylines on separate layers for major and minor contours, typically with elevation labels.
As-built drawings
Measurements of completed construction, compared against design. DXF as-built drawings overlay the constructed features on the design drawing to verify compliance.
Site plans
Simple plans showing site layout for development applications, construction planning, or client communication. Often derived from feature survey data with selective layer visibility.
Cross-sections
Terrain and design cross-sections extracted at regular intervals along a corridor or across a site. Each section is typically a polyline showing the ground profile and design profile.
How to create DXF files
From CAD software
AutoCAD / Civil 3D: File > Save As > choose DXF format > select version (2018, 2013, 2010, 2007, 2004, 2000, R12). For maximum compatibility, save as AutoCAD 2010 DXF or 2000 DXF. Civil 3D surfaces and alignments won’t export directly — explode them to basic geometry first.
QGIS: Layer > Export > Save Features As > DXF. QGIS can export vector layers to DXF, converting polygons to polylines and preserving attributes as text.
Global Mapper: File > Export > Export DXF. Useful for converting between formats — import a shapefile, GeoJSON, or KML and export as DXF.
12d Model / Trimble Business Center / Leica Infinity: Survey-specific CAD platforms all support DXF export. The quality of the export varies — always check layer structure and entity types after export.
From point clouds
Several tools can extract DXF features from point cloud data:
CloudCompare: Extract cross-sections, contour lines, or traced polylines and export as DXF.
Virtual Surveyor: Specialised tool for extracting survey deliverables (contours, breaklines, spot heights) from drone point clouds and exporting as DXF.
AutoCAD with point cloud import: Import LAS/LAZ, trace features manually or with feature extraction tools, save as DXF.
How to view DXF files
Desktop viewers (free)
- Autodesk TrueView — Free DXF/DWG viewer from Autodesk.
- eDrawings — Free viewer from SolidWorks, supports DXF.
- QGIS — Open-source GIS, opens DXF as vector layers.
- LibreCAD — Open-source 2D CAD, reads and writes DXF.
- FreeCAD — Open-source 3D CAD, imports DXF.
Browser-based viewing
The challenge with DXF delivery is that most clients don’t have CAD software. Sending a DXF to an architect is fine — they’ll open it in AutoCAD. Sending a DXF to a property developer, a lawyer, or a project manager is problematic — they have nothing to open it with.
Swyvl solves this by rendering DXF files directly in the browser. Upload a DXF, share a link, and your client can view, pan, zoom, and toggle layers without installing anything. Layers are preserved, so the client can turn features on and off just like in CAD.
For a broader look at survey deliverable formats, see What File Formats Do Drone Surveys Produce?
DXF version compatibility
DXF has been updated with each AutoCAD release since 1982. Key versions:
| DXF version | AutoCAD version | Year | Notes |
|---|---|---|---|
| R12 | AutoCAD Release 12 | 1992 | Widely supported, very basic |
| R14 | AutoCAD Release 14 | 1997 | Added splines, improved text |
| 2000 | AutoCAD 2000 | 1999 | LWPOLYLINE, major format update |
| 2004 | AutoCAD 2004 | 2003 | Table objects, improved MText |
| 2007 | AutoCAD 2007 | 2006 | Unicode support, annotation scaling |
| 2010 | AutoCAD 2010 | 2009 | Mesh objects, 3D improvements |
| 2013 | AutoCAD 2013 | 2012 | Minor updates |
| 2018 | AutoCAD 2018 | 2017 | Current widely-used version |
My recommendation: Export as AutoCAD 2010 DXF for general delivery. It supports all common entity types and is compatible with virtually every CAD application in use today. Only use 2000 or R12 if the receiving software specifically requires it (some older GIS and CNC systems do).
Common issues with DXF files
Missing fonts
DXF files reference font files (SHX or TrueType) for text display. If the receiving system doesn’t have the same fonts, text may display incorrectly or not at all. Common culprits: custom SHX fonts used by survey software.
Fix: Use standard fonts (Arial, Romans, Simplex) for deliverable DXFs. Or embed the SHX files alongside the DXF.
Coordinate system confusion
DXF files don’t embed coordinate reference system (CRS) metadata the way GeoTIFFs or shapefiles do. The coordinates in the file are just numbers — the recipient must know what CRS they’re in.
Fix: Always state the CRS in your deliverable documentation, file naming, or drawing title block. Example: “All coordinates are MGA2020 Zone 56 (EPSG:7856). Heights are AHD.”
Units
DXF files don’t enforce units. If you draw in metres but the recipient opens in feet (or millimetres), everything scales wrong.
Fix: Specify units in the drawing header (INSUNITS variable) and in your documentation.
Large file sizes
ASCII DXF files with dense contour data or detailed geometry can be very large — hundreds of megabytes. This makes them difficult to email.
Fix: Use binary DXF (smaller than ASCII) or compress the file. For web delivery, upload to Swyvl and share a link instead of emailing the file. See File Sharing for Surveyors for more options.
Entity explosion
When exporting from Civil 3D or other vertical products, complex objects (surfaces, corridors, pipe networks) are sometimes “exploded” into thousands of individual 3DFACE or LINE entities. This makes the DXF technically correct but difficult to work with.
Fix: Explode complex objects intentionally before export, organising the results onto appropriate layers. Or export only the layers you intend to deliver.
DXF vs other survey delivery formats
| Format | Best for | Open? | Preserves layers? | Geo-referenced? |
|---|---|---|---|---|
| DXF | 2D CAD drawings | Yes | Yes | No (by convention only) |
| DWG | Working CAD files | No | Yes | No (by convention only) |
| Shapefile | GIS vector data | Yes | Via attributes | Yes |
| GeoJSON | Web GIS | Yes | Via properties | Yes |
| GeoPackage | Modern GIS exchange | Yes | Via attributes | Yes |
| Non-technical viewing | Yes | No | Optional (GeoPDF) | |
| GeoTIFF | Raster/elevation data | Yes | No | Yes |
DXF occupies a unique niche: it’s the standard for delivering structured 2D vector drawings with layers, line types, and annotations. Shapefiles and GeoJSON are better for GIS integration, but they don’t carry the drafting information (dimensions, hatches, blocks, text styles) that a DXF does.
For many projects, the best approach is to deliver both: DXF for the design/construction team and a shareable web link for everyone else. Upload the DXF to Swyvl, and you cover both audiences from one platform.
Summary
- DXF is the open standard for CAD data exchange — it works everywhere that DWG doesn’t.
- Survey DXF files contain layers, polylines, text, points, and blocks representing site features, boundaries, contours, and annotations.
- Export as AutoCAD 2010 DXF for maximum compatibility.
- Always document the CRS and units — DXF doesn’t embed this metadata.
- For client delivery, upload DXF to a platform with browser viewing so non-CAD users can access the data. Swyvl renders DXF files directly in the browser with layer control.
- DXF and DWG coexist: work in DWG, deliver in DXF. Or deliver both.
For more on survey file formats, see What File Formats Do Drone Surveys Produce? and explore Swyvl’s pricing to see how DXF viewing fits into the platform.