Free webp to jpg
EN
Image MIME Reference
JNG

JPEG Network Graphics

image/x-jng
VS

MacPaint Image

image/x-macpaint
MacPaint

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

Equal browser support

Feature Support

Feature JNG MacPaint
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 →
MacPaint Image
image/x-macpaint
Extension
.mac.pntg.pnt.macp
Container Raw pixel payload with a 512-byte pattern header
Compression PackBits (Run-Length Encoding)
Algorithm
PackBits (Apple RLE)
Color Depth 1-bit (Monochrome)
Developed by Apple Computer, Inc. (Bill Atkinson)
Released 1984
Magic Bytes
None (Relies on classic Mac OS 'PNTG' OSType)
Full MacPaint reference →

Browser Support Comparison

Browser JNG MacPaint
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  • Completely obsolete today, having been superseded by natively supported, superior formats like WebP, AVIF, and HEIC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
MacPaint

MacPaint Strengths

  • Profoundly historically significant as the format that introduced millions to the concept of bitmap digital painting
  • Extremely simple PackBits compression makes it easy for emulator developers or archivists to write parsers from scratch in under an hour
Limitations
  • Severely limited: strictly black and white, and hard-locked to exactly 576 x 720 pixels
  • Lack of standard magic bytes makes programmatic file sniffing unreliable on modern filesystems without relying on the file extension
  • Completely obsolete and unsupported by modern web browsers or consumer image viewers

When to choose which format

JNG
Use JNG when…
  • Embedded frames in MNG animations
  • Historical web graphics requiring lossy compression with transparency
MacPaint
Use MacPaint when…
  • Historical Apple Macintosh Archival
  • Early 1980s Digital Art Preservation
  • Retro UI/UX Academic Research

More comparisons

JNG vs ACES → MacPaint vs ACES → JNG vs APNG → MacPaint vs APNG → JNG vs AVCI → MacPaint vs AVCI → JNG vs AVCS → MacPaint vs AVCS → JNG vs AVIF → MacPaint vs AVIF → All comparisons →
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