Image MIME Reference
SLD
AutoCAD Slide
image/vnd.sld
VS
Tagged Image File Format (Legacy MIME)
image/x-tiff
TIFF
A complete technical comparison of AutoCAD Slide and Tagged Image File Format (Legacy MIME) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | SLD | TIFF |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
AutoCAD Slide
image/vnd.sld
Extension
.sld
Container
AutoCAD Slide Container
Compression
Uncompressed (Vector Instructions)
Algorithm
None
Color Depth
8-bit (AutoCAD Indexed Color)
Developed by
Autodesk, Inc.
Released
1980s
Magic Bytes
41 75 74 6F 43 41 44 20 53 6C 69 64 65 0D 0A 1A 00
Tagged Image File Format (Legacy MIME)
image/x-tiff
Extension
.tiff.tif
Container
IFD (Image File Directory) Tag Structure
Compression
Uncompressed / LZW (Lossless) / ZIP / Deflate (Lossless) / PackBits (Lossless RLE) / JPEG (Lossy) / CCITT Group 3/4 (Fax/Document)
Algorithm
NoneLZWDeflatePackBitsJPEGCCITT
Color Depth
1-bit (Monochrome), 8-bit (Grayscale or Indexed), 16-bit (Per Channel), 32-bit (Float Per Channel)
Developed by
Aldus Corporation (Later acquired by Adobe Systems)
Released
1986
Magic Bytes
49 49 2A 00 (Little-endian) or 4D 4D 00 2A (Big-endian)
Browser Support Comparison
| Browser | SLD | TIFF |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
SLD
SLD Strengths
- Allowed for instantaneous loading of highly complex architectural and engineering blueprints on low-memory MS-DOS systems
- Easy-to-parse binary structure containing simple opcodes for drawing vectors and polygons
Limitations
- Completely obsolete and heavily fragmented, largely replaced by PDF and lightweight web-based DXF viewers
- Destructive 'snapshot' format irrevocably strips all useful, editable CAD geometry data from the original drawing
- Zero support in web browsers or standard image processing libraries
TIFF
TIFF Strengths
- Universally accepted as the gold standard for high-fidelity archival and professional print workflows
- Highly adaptable structure supports multiple pages (documents), layers, vast bit depths, and diverse compression algorithms within a single file
- Unmatched support for rich metadata including EXIF, IPTC, XMP, and custom ICC color profiles
Limitations
- Produces exceptionally large file sizes compared to modern web formats
- The 'x-tiff' legacy MIME string forces developers to write extra validation logic to prevent strict security filters from rejecting valid uploads
- The format's immense complexity means that many lightweight parsers only implement a subset of the specification, sometimes failing to read obscure compressions (like CCITT or old JPEG-in-TIFF)
When to choose which format
SLD
Use SLD when…
- Legacy AutoCAD Slideshows
- AutoCAD Custom Icon Menus
- Historical CAD Archival
TIFF
Use TIFF when…
- Professional Print and Desktop Publishing
- High-Resolution Archival Scanning
- Master Copies of Digital Photography