Free webp to jpg
Image MIME Reference
JNG

JPEG Network Graphics

image/x-jng
VS

Extended Image File Format

image/vnd.xiff
XIFF

A complete technical comparison of JPEG Network Graphics and Extended Image File Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JNG XIFF
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG Network Graphics
image/x-jng
Extension
.jng
Container PNG-style Chunk Structure (JHDR, JDAT, IDAT, IEND)
Compression Lossy (JPEG/DCT for color) / Lossless (Deflate for alpha mask)
Algorithm
JPEG (Discrete Cosine Transform)Deflate (LZ77)
Color Depth 8-bit, 12-bit, 24-bit (RGB), 32-bit (RGBA)
Developed by MNG Development Group (Glenn Randers-Pehrson et al.)
Released 2001
Magic Bytes
8B 4A 4E 47 0D 0A 1A 0A
Full JNG reference →
Extended Image File Format
image/vnd.xiff
Extension
.xif
Container TIFF-based Proprietary Container
Compression CCITT Group 3 / Group 4 / LZW / Uncompressed
Algorithm
CCITT Group 4LZWNone
Color Depth 1-bit (Monochrome), 8-bit (Grayscale), 24-bit (RGB)
Developed by Keyfile Corporation
Released 1994
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
Full XIFF reference →

Browser Support Comparison

Browser JNG XIFF
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
JNG

JNG Strengths

  • Solved a massive technical hurdle in the early 2000s by combining high-compression lossy photographic data with crisp, 8-bit alpha transparency
  • Utilized the highly robust, extensible chunk-based architecture of the PNG format
  • Provided an excellent, bandwidth-saving alternative to massive 32-bit transparent PNGs for web design
Limitations
  • Failed to achieve critical mass; browser vendors largely abandoned the MNG/JNG standard due to implementation complexity
  • Completely obsolete today, having been superseded by natively supported, superior formats like WebP, AVIF, and HEIC
  • Decoding requires a hybrid engine that can parse PNG chunks while simultaneously decoding a JPEG stream and a Deflate stream, complicating software support
XIFF

XIFF Strengths

  • Pioneered early enterprise document workflow integration by binding administrative routing data directly to the document image file
  • Leveraged efficient fax compression standards to keep storage requirements low on 1990s server infrastructure
Limitations
  • Completely proprietary and obsolete; Keyfile Corporation's software ecosystem no longer exists
  • Causes widespread MIME type identification conflicts due to sharing the exact same binary header signature as standard TIFF files
  • Zero support in modern operating systems or web browsers

When to choose which format

JNG
Use JNG when…
  • Embedded frames in MNG animations
  • Historical web graphics requiring lossy compression with transparency
XIFF
Use XIFF when…
  • Keyfile Enterprise Document Management
  • Legacy Corporate Workflow Archival
  • Scanned Multi-page Document Routing
Share this comparison