Free webp to jpg
EN
Image MIME Reference
APNG

Animated Portable Network Graphics

image/vnd.mozilla.apng
VS

Portable Anymap

image/x-portable-anymap
PNM

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

APNG wins on browser support

Feature Support

Feature APNG PNM
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
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 →
Portable Anymap
image/x-portable-anymap
Extension
.pnm
Container Netpbm
Compression Uncompressed
Algorithm
None
Color Depth 1-bit (PBM), 8-bit to 16-bit (PGM), 24-bit to 48-bit (PPM)
Developed by Jef Poskanzer (Netpbm Project)
Released 1988
Magic Bytes
50 31, 50 32, 50 33, 50 34, 50 35, or 50 36
Full PNM reference →

Browser Support Comparison

Browser APNG PNM
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)
PNM

PNM Strengths

  • Unparalleled simplicity: parsers and writers for PNM files can be written from scratch in C or Python in just a few minutes without relying on external libraries
  • Serves as an excellent foundational teaching tool for computer science students learning about image arrays and raster graphics
  • Flawlessly pipes through Unix command-line utilities for robust automated image processing (via the Netpbm suite)
Limitations
  • Zero compression natively results in astronomical file sizes, making it entirely impractical for web delivery or consumer storage
  • No support for standard metadata formats like EXIF, XMP, or ICC color profiles
  • No native alpha channel support in the classic PNM specification (though the newer PAM format 'P7' addresses this)

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
PNM
Use PNM when…
  • Unix/Linux Command-Line Image Processing (Netpbm suite)
  • Academic Computer Vision Research
  • Intermediary Format for Image Format Conversion

More comparisons

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