What is the DWF file format?
The .dwf (Design Web Format) file is designed to store 2D/3D drawings used by various CAD design applications. The format was created by Autodesk. .dwf files can hold design data, including 2D raster graphics, 3D models, and text. A .dwf file can have a simple structure composed of only a single sheet, or can be very complex and contain multiple embedded resources such as fonts, colors, and images.
Modern .dwf files (version 6 and later, introduced around 2005) use a ZIP archive as their container - identifiable by the PK magic bytes at the file start. Older pre-version-6 files begin with an ASCII (DWF V header string instead. A closely related variant, .dwfx, packages the same content in an XPS/OPC archive and can be opened directly in the Windows built-in XPS viewer.
The purpose of the .dwf format
The .dwf format was created to facilitate CAD project distribution. The main goal is to provide a lightweight publishing format - not to replace the standard formats used in the CAD software environment such as .dwg or .dxf - but to enable recipients to open and review project files without needing access to full CAD software.
.dwf format advantages
- A
.dwffile is a highly compressed CAD file, and thus is more accessible for viewing, printing and sharing because the file size is significantly smaller than that of the original source file. - The
.dwffile structure enables selective reduction of project data and print styles so the author can share only the information they want to share. .dwffiles maintain high mathematical precision and contain metadata for sheets, objects and markup data.
Security & safety
RISK: LOWDWF files are published, view-only CAD data and don't execute code, so opening them in a viewer is safe. The realistic concerns are non-malware: a DWF can disclose proprietary design detail (it's measurable geometry), so treat shared files as sensitive; and download viewers only from Autodesk (autodesk.com) - there are fake-'DWF viewer' download sites bundling adware/PUPs around this niche format. Design Review being unmaintained is a maintenance/compatibility caveat, not a security exploit, but for untrusted files the browser-based Autodesk Viewer is the safest option.
Format details
in a nutshellMAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
504B0304
ASCII
PK··
Modern DWF (version 6 and later, since ~2005) is a ZIP package, so it starts with the ZIP "PK" header (50 4B 03 04). Older DWF (v00.xx/ASCII or pre-6 binary) begins with the ASCII text "(DWF V" version string instead. DWFx is a different beast: an XPS/OPC package (also ZIP-based, "PK") that opens in Windows' XPS viewer. Identify by the internal DWF manifest, not the generic PK header alone.
Programs that open DWF files
Windows6 apps
Autodesk Design Review
Free Free Windows desktop viewer - open the DWF to view, measure, redline/markup and print. Note: frozen at the 2018 release (no longer developed), but still the fullest DWF markup tool. 
DWG TrueView
Free Autodesk's free DWG/DWF viewer - open and plot DWF; also useful alongside DWG work. 
Autodesk Viewer (web)
Free Upload the DWF at viewer.autodesk.com (free account) to view, measure and mark up in any browser - the recommended modern viewer; no install.
XPS Viewer (DWFx only)
Built-in A .dwfx is XPS-based - install the optional Windows XPS Viewer feature and open it directly. (Plain .dwf won't open here.) 
macOS2 apps
Autodesk Viewer (web)
Free Design Review is Windows-only - on macOS use the browser-based Autodesk Viewer to view/measure DWF.
Web2 apps
Autodesk Viewer
Free Drag the DWF onto viewer.autodesk.com to view, measure, section and mark up online - works on any OS. Technical details
deep spec| Container structure | Version 6+ (since ~2005): ZIP package (magic bytes PK / 50 4B 03 04); pre-version-6: ASCII text file starting with "(DWF V" header string |
| MIME type | model/vnd.dwf |
| 2D geometry stream | Internal .w2d stream encodes 2D vector and raster data using the Whip! format |
| 3D geometry stream | Internal .w3d stream encodes 3D scene geometry, materials and viewpoints |
| Coordinate precision | Double-precision floating-point (64-bit) coordinates for high mathematical accuracy |
| Compression | ZIP deflate compression applied per-stream, significantly reducing file size compared to the original .dwg source |
| Multi-sheet support | A single .dwf package can contain multiple sheets, layouts and model views |
| Embedded metadata | Sheet-level, object-level and markup/annotation metadata stored per Autodesk DWF specification |
| Markup/annotation layer | Supports embedded reviewer markups (comments, stamps, measurements) without altering source geometry |
| Selective publishing | Author controls which layers, attributes and drawing objects are included at publish time |
| Font embedding | TrueType and other font resources can be embedded directly inside the ZIP package |
| Raster image support | PNG, JPEG and other raster images can be embedded alongside vector geometry within the package |
| XPS variant | .dwfx (since 2007) repackages the same content as an XPS/OPC container, natively viewable in Windows XPS Viewer |
| View-only intent | Published format designed for review and distribution; editing requires returning to the original CAD source file |
| Released | 1995 (DWF by Autodesk); modern ZIP-based DWF since ~2005, DWFx (XPS-based) since 2007 |
| Specification | www.autodesk.com |
DWF conversions
Possible
.DWF .PDFGUIDE
Yes -- the quickest free route on Windows is Autodesk Design Review: open the DWF, go to File > Print, select…
How to convert
.DWF .JPGGUIDE
Yes, DWF can be converted to JPG - the fastest way is to open the file in Autodesk Viewer (free,…
How to convert
.DWF .DWFXGUIDE
Yes - re-publish the DWF as DWFX in AutoCAD or Autodesk Design Review (free).
How to convert
.DWF .DXFGUIDE
Yes, DWF can be converted to DXF using AnyDWG's converter or AutoCAD, but the output is lossy because DWF is…
How to convert
.DWF .DWGGUIDE
Yes, DWF can be converted to DWG - the most direct desktop tool is Any DWF to DWG Converter by AnyDWG, but…
How to convert
Not possible
Community Q&A
asked by users
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Frequently asked questions
How do I open a DWF file for free?
Upload it to Autodesk Viewer (viewer.autodesk.com) in a browser - free, no install, works on any OS. On Windows you can also use the free Autodesk Design Review or DWG TrueView. A .dwfx additionally opens in Windows' XPS Viewer.
What is a DWF file?
A Design Web Format file - a compressed, view-only published version of an AutoCAD/Autodesk design (2D drawing or 3D model), made for sharing, reviewing, measuring and printing without the editable DWG. Think of it as a PDF for CAD.
What's the difference between DWF and DWG?
DWG is the editable native AutoCAD drawing. DWF is a published, view-only snapshot of a design for sharing/review - you can measure and mark it up but not edit the design. You can't reliably turn a DWF back into a full DWG.
How do I convert DWF to DWG?
Tools like AnyDWG's 'Any DWF to DWG Converter' or AutoCAD can do it, but the result is lossy because DWF is a published derivative. The better answer is to ask whoever sent it for the original DWG file.
What is a DWFx file and why does it open in XPS Viewer?
DWFx is the XPS-based variant of DWF (Microsoft's XPS/OPC packaging), so Windows' built-in XPS Viewer can open it. It's the same view-only design data as DWF, just packaged differently.
Is Autodesk Design Review still available?
Yes, the free download still works, but Autodesk no longer develops it (frozen at the 2018 release). It remains the fullest DWF markup/redline tool on Windows; for new or cross-platform use, Autodesk Viewer in the browser is recommended.
References
1Wikipedia - Design Web Format (DWF/DWFx)en.wikipedia.org
2Autodesk - Design Review (free DWF viewer)www.autodesk.com
