Free webp to jpg
EN
Image MIME Reference
AVIF

AV1 Image File Format

image/avif
VS

Microsoft Image Extension

image/vnd.mix
MIX

A complete technical comparison of AV1 Image File Format and Microsoft Image Extension — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

AVIF wins on browser support

Feature Support

Feature AVIF MIX
Transparency (Alpha) Yes Yes
Animation Support Yes ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes Yes
AV1 Image File Format
image/avif
Extension
.avif
Container HEIF / ISOBMFF
Compression AV1 Lossy / AV1 Lossless
Algorithm
AV1
Color Depth 8-bit, 10-bit, 12-bit
Developed by Alliance for Open Media (AOMedia)
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 69 66
Full AVIF reference →
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 →

Browser Support Comparison

Browser AVIF MIX
Chrome Chrome
✓ 85+
 ✕
Firefox Firefox
✓ 93+
 ✕
Safari Safari
✓ 16+
 ✕
Edge Edge
✓ 121+
 ✕
IE IE (Legacy)
✕ ✕
AVIF

AVIF Strengths

  • Best-in-class compression — typically 20–50% smaller than WebP at equivalent quality
  • Native HDR and wide color gamut (BT.2020) support
  • Supports 8, 10, and 12-bit color depth
Limitations
  • Encoding is highly CPU-intensive — significantly slower than JPEG or WebP
  • Requires Edge 121+ (not supported in earlier Edge versions)
  • Limited support in native desktop image viewers
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

When to choose which format

AVIF
Use AVIF when…
  • Next-Gen Websites
  • HDR Photography
  • High-Quality Web Images
MIX
Use MIX when…
  • Historical Microsoft Picture It! Projects
  • Microsoft PhotoDraw 2000 Graphics
  • Early 2000s Consumer Digital Scrapbooking

More comparisons

AVIF vs ACES → MIX vs ACES → AVIF vs APNG → MIX vs APNG → AVIF vs AVCI → MIX vs AVCI → AVIF vs AVCS → MIX vs AVCS → All comparisons →
Share this comparison