Image MIME Reference
JPEG
JPEG Image
image/jpeg
VS
MacPaint Image
image/x-macpaint
MacPaint
A complete technical comparison of JPEG Image and MacPaint Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
JPEG wins on browser support
Feature Support
| Feature | JPEG | MacPaint |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
JPEG Image
image/jpeg
Extension
.jpg.jpeg.jpe.jfif
Container
JFIF / Exif
Compression
Lossy
Algorithm
DCT (Discrete Cosine Transform)
Color Depth
8-bit
Developed by
Joint Photographic Experts Group
Released
1992
Magic Bytes
FF D8 FF
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 | JPEG | MacPaint |
|---|---|---|
Chrome
|
✓ All
|
✕ |
Firefox
|
✓ All
|
✕ |
Safari
|
✓ All
|
✕ |
Edge
|
✓ All
|
✕ |
IE (Legacy)
|
✓
|
✕ |
JPEG
JPEG Strengths
- Universal support — every browser, OS, and application handles JPEG
- Excellent compression for complex photographs with natural color gradients
- Rich metadata support: EXIF (GPS, camera settings), ICC color profiles
Limitations
- No transparency — cannot have a transparent background
- Lossy compression introduces visible artifacts on sharp edges and text
- No animation 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
JPEG
Use JPEG when…
- Photography
- Websites
- Social Media
MacPaint
Use MacPaint when…
- Historical Apple Macintosh Archival
- Early 1980s Digital Art Preservation
- Retro UI/UX Academic Research