Image MIME Reference
DXF
Drawing Exchange Format
image/vnd.dxf
VS
Microsoft Document Imaging
image/vnd.ms-modi
MODI
A complete technical comparison of Drawing Exchange Format and Microsoft Document Imaging — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DXF | MODI |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
Drawing Exchange Format
image/vnd.dxf
Extension
.dxf
Container
Text / Binary Container
Compression
Uncompressed (ASCII) / Uncompressed (Binary)
Algorithm
None
Color Depth
Vector (Indexed AutoCAD Colors / True Color)
Developed by
Autodesk
Released
1982
Magic Bytes
30 0D 0A 53 45 43 54 49 4F 4E (ASCII) / 41 75 74 6F 43 41 44 20 42 69 6E 61 72 79 20 44 58 46 0D 0A 1A 00 (Binary)
Microsoft Document Imaging
image/vnd.ms-modi
Extension
.mdi
Container
TIFF Variant
Compression
LZW / Proprietary MS Compression
Algorithm
LZW (Modified)
Color Depth
1-bit (Monochrome), 8-bit (Grayscale), 24-bit (RGB)
Developed by
Microsoft Corporation
Released
2001
Magic Bytes
49 49 2A 00
Browser Support Comparison
| Browser | DXF | MODI |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DXF
DXF Strengths
- Universally supported by almost every CAD program, 3D modeler, and vector graphics editor in existence
- ASCII structure is human-readable and can be parsed or generated programmatically with relative ease
- The de facto standard for sending 2D cutting paths to CNC routers, plasma cutters, and laser engravers
Limitations
- ASCII DXF files can be enormously large and inefficient compared to binary DWG files
- The format relies heavily on legacy AutoCAD data structures, making complex 3D entity parsing extremely difficult for third-party developers
- Lacks native web browser rendering capabilities
MODI
MODI Strengths
- Historically provided an excellent all-in-one scanned document format with built-in OCR and annotations before PDF editing became universally accessible
- Tightly integrated with Microsoft Office and SharePoint workflows in the early 2000s
Limitations
- Completely proprietary and obsolete; Microsoft abandoned it in favor of standard TIFF and PDF
- Causes widespread identification conflicts since its file signature is identical to a standard TIFF
- Extremely difficult to open on modern operating systems without relying on third-party conversion utilities
When to choose which format
DXF
Use DXF when…
- Cross-Platform CAD Data Exchange
- CNC Machining and Laser Cutting Paths
- PCB Design Outlines
- Architectural 2D Layouts
MODI
Use MODI when…
- Legacy Scanned Document Archival
- Microsoft Office XP/2003/2007 Workflows
- Embedded OCR Text Storage