Image MIME Reference
APNG
Animated Portable Network Graphics
image/vnd.mozilla.apng
VS
MacPaint Image
image/x-macpaint
MacPaint
A complete technical comparison of Animated Portable Network Graphics and MacPaint Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
APNG wins on browser support
Feature Support
| Feature | APNG | MacPaint |
|---|---|---|
| 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
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)
Browser Support Comparison
| Browser | APNG | MacPaint |
|---|---|---|
|
|
✓ 59
|
✕ |
|
|
✓ 3
|
✕ |
|
|
✓ 8
|
✕ |
|
|
✓ 79
|
✕ |
|
|
✕ | ✕ |
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)
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
APNG
Use APNG when…
- High-Quality Web Animations
- Stickers (Apple iMessage, LINE, Discord)
- UI Loaders with Alpha Transparency
- GIF Replacement
MacPaint
Use MacPaint when…
- Historical Apple Macintosh Archival
- Early 1980s Digital Art Preservation
- Retro UI/UX Academic Research