Free webp to jpg
Image MIME Reference
APNG

Animated Portable Network Graphics

image/vnd.mozilla.apng
VS

Windows Enhanced Metafile

image/x-emf
EMF

A complete technical comparison of Animated Portable Network Graphics and Windows Enhanced Metafile — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

APNG wins on browser support

Feature Support

Feature APNG EMF
Transparency (Alpha) Yes Yes
Animation Support Yes ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes Yes
Animated Portable Network Graphics
image/vnd.mozilla.apng
Extension
.apng.png
Container PNG Chunk Stream
Compression Deflate (Lossless)
Algorithm
Deflate (zlib)
Color Depth 8-bit (Indexed), 24-bit (TrueColor), 32-bit (RGBA)
Developed by Mozilla Corporation (Stuart Parmenter & Vladimir Vukićević)
Released 2004
Magic Bytes
89 50 4E 47 0D 0A 1A 0A
Full APNG reference →
Windows Enhanced Metafile
image/x-emf
Extension
.emf
Container Windows GDI/GDI+ Record Sequence
Compression Uncompressed (Binary Drawing Records)
Algorithm
None
Color Depth Vector (32-bit GDI/GDI+ Colors), Supports embedded 24-bit/32-bit bitmaps
Developed by Microsoft Corporation
Released 1993
Magic Bytes
01 00 00 00 (Header Type) ... 20 45 4D 46 (Signature at offset 40)
Full EMF reference →

Browser Support Comparison

Browser APNG EMF
Chrome Chrome
✓ 59
Firefox Firefox
✓ 3
Safari Safari
✓ 8
Edge Edge
✓ 79
IE IE (Legacy)
APNG

APNG Strengths

  • Supports 8-bit alpha transparency, completely solving the ugly 'white halo' problem inherent to GIFs
  • Gracefully degrades; viewers that do not support APNG will render a perfectly valid, static PNG of the first frame
  • Provides lossless compression that retains absolute pixel-perfect quality for UI elements and line art
Limitations
  • Because it relies on lossless Deflate compression, file sizes for complex, video-like animations can be massive compared to lossy formats like WebP or AVIF
  • Was initially rejected by the official PNG group, delaying its adoption for nearly a decade
  • Lacks native hardware decoding acceleration, unlike video-based animated formats (like MP4 or WebM)
EMF

EMF Strengths

  • Device independent, meaning it renders consistently across different monitors and printers regardless of resolution
  • Fully supports 32-bit precision and advanced GDI+ drawing commands, including alpha transparency and anti-aliasing (EMF+)
  • Native rendering within the Windows OS ensures fast performance and flawless fidelity in Microsoft Office applications
Limitations
  • Heavily tied to the Windows Graphics Device Interface API, making it notoriously difficult to parse perfectly on macOS or Linux
  • Completely unsupported by modern web standards; cannot be embedded in HTML without conversion to SVG
  • Security history: Like WMF, malicious drawing records can theoretically exploit vulnerabilities in older GDI parsers

When to choose which format

APNG
Use APNG when…
  • High-Quality Web Animations
  • Stickers (Apple iMessage, LINE, Discord)
  • UI Loaders with Alpha Transparency
  • GIF Replacement
EMF
Use EMF when…
  • Microsoft Office Vector Graphics and Clip Art
  • Windows Print Spooling (EMF Spool Files)
  • High-fidelity Vector Interchange on Windows
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