Free webp to jpg
Image MIME Reference
MIX

Microsoft Image Extension

image/vnd.mix
VS

Valve Texture Format

image/vnd.valve.source.texture
VTF

A complete technical comparison of Microsoft Image Extension and Valve Texture Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature MIX VTF
Transparency (Alpha) Yes Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No ✕ No
HDR Support ✕ No Yes
EXIF Metadata ✕ No ✕ No
ICC Color Profile Yes ✕ No
Microsoft Image Extension
image/vnd.mix
Extension
.mix
Container Microsoft OLE Structured Storage (COM)
Compression Proprietary (Internal JPEG/RLE)
Algorithm
JPEGDeflateProprietary
Color Depth 8-bit, 24-bit, 32-bit (RGBA)
Developed by Microsoft Corporation
Released 1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
Full MIX reference →
Valve Texture Format
image/vnd.valve.source.texture
Extension
.vtf
Container Valve Texture Format Header
Compression DXTC (DXT1, DXT3, DXT5) / Uncompressed (BGRA8888, RGB888, etc.)
Algorithm
DXT1-DXT5None
Color Depth 8-bit, 24-bit (RGB), 32-bit (RGBA), 16-bit Floating Point (HDR)
Developed by Valve Corporation
Released 2004
Magic Bytes
56 54 46 00
Full VTF reference →

Browser Support Comparison

Browser MIX VTF
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
MIX

MIX Strengths

  • Allowed early consumer software to non-destructively edit complex compositions involving photos, text, and vector clipart
  • Shared an architecture with other Microsoft Office products, enabling deep integration (OLE embedding) into Word and PowerPoint at the time
Limitations
  • Completely proprietary and undocumented, leading to a massive loss of historical data for users who archived their family photos in this project format
  • Requires traversing a complex OLE filesystem just to extract the flattened raster image
  • No support in modern image editors like Photoshop, GIMP, or web browsers
VTF

VTF Strengths

  • Extremely fast loading within the Source Engine because the block-compressed data goes directly into the GPU's VRAM without CPU decompression overhead
  • Bundles mipmaps, volumetric slices, cubemap faces, and animation frames entirely within a single file
  • Openly documented by the Valve Developer Community, leading to a massive ecosystem of third-party modding tools
Limitations
  • Strictly tied to the Source Engine ecosystem; entirely useless in standard web or print contexts
  • No native support in standard image editors without hunting down and installing specialized plugins
  • Block compression algorithms (DXT) are lossy and can cause visible artifacting, especially on normal maps or smooth gradients

When to choose which format

MIX
Use MIX when…
  • Historical Microsoft Picture It! Projects
  • Microsoft PhotoDraw 2000 Graphics
  • Early 2000s Consumer Digital Scrapbooking
VTF
Use VTF when…
  • Source Engine Game Textures
  • Custom Maps and Modding (Garry's Mod, CS:GO)
  • Animated In-Game Decals and Sprays
  • Environment Cubemaps (Skyboxes)
Share this comparison