Free webp to jpg
Image MIME Reference
DDS

DirectDraw Surface

image/vnd.ms-dds
VS

AutoCAD Slide

image/vnd.sld
SLD

A complete technical comparison of DirectDraw Surface and AutoCAD Slide — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature DDS SLD
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No ✕ No
DirectDraw Surface
image/vnd.ms-dds
Extension
.dds
Container DirectDraw Surface
Compression Block Compression (BC1-BC7) / DXTC / S3TC / Uncompressed (RGBA, Floating-Point)
Algorithm
DXT1-DXT5BC1-BC7ASTC / ETC2 (Extended)
Color Depth 8-bit, 16-bit, 24-bit, 32-bit (RGBA), 16-bit/32-bit Floating Point (HDR)
Developed by Microsoft Corporation
Released 1999
Magic Bytes
44 44 53 20
Full DDS reference →
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
Full SLD reference →

Browser Support Comparison

Browser DDS SLD
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
DDS

DDS Strengths

  • Massively reduces VRAM footprint and memory bandwidth usage because the GPU decodes the block compression in hardware
  • Encapsulates complex texture arrays, volume textures, cubemaps, and entire mipmap chains within a single, highly structured file
  • Supports high-dynamic-range (HDR) floating-point data for modern physically based rendering (PBR)
Limitations
  • Block compression algorithms (like DXT) are lossy and can introduce ugly blocky artifacts, especially in smooth gradients or normal maps if not tuned properly
  • Files are generally larger on the physical hard drive than highly compressed formats like PNG or WebP
  • Zero support in web browsers or standard consumer image viewers
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

When to choose which format

DDS
Use DDS when…
  • Real-Time 3D Game Textures
  • DirectX and Vulkan Rendering Pipelines
  • Skyboxes and Environment Cubemaps
  • Volume Textures (3D Textures)
SLD
Use SLD when…
  • Legacy AutoCAD Slideshows
  • AutoCAD Custom Icon Menus
  • Historical CAD Archival
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