Image MIME Reference
FreeHand
Macromedia FreeHand Document
image/x-freehand
VS
Progressive JPEG (Legacy IE Alias)
image/pjpeg
PJPEG
A complete technical comparison of Macromedia FreeHand Document and Progressive JPEG (Legacy IE Alias) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
PJPEG wins on browser support
Feature Support
| Feature | FreeHand | PJPEG |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | Yes | Yes |
Macromedia FreeHand Document
image/x-freehand
Extension
.fh.fh4.fh5.fh7.fh8.fh9.fh10.fh11.ft11
Container
Proprietary Binary (Aldus Graphic Document)
Compression
Uncompressed / Deflate (in later versions)
Algorithm
NoneDeflate (Optional in later versions)
Color Depth
Vector Data (RGB/CMYK)
Developed by
Altsys / Aldus / Macromedia
Released
1988
Magic Bytes
41 47 44 31 to 41 47 44 34
Progressive JPEG (Legacy IE Alias)
image/pjpeg
Extension
.jpeg.jpg.pjpeg.pjp.jfif
Container
JPEG (ISO/IEC 10918-1)
Compression
Lossy (DCT)
Algorithm
Discrete Cosine Transform (DCT)
Color Depth
8-bit, 12-bit
Developed by
Joint Photographic Experts Group / Microsoft (Alias)
Released
1992
Magic Bytes
FF D8 FF E0 (JFIF) / FF D8 FF E1 (Exif)
Browser Support Comparison
| Browser | FreeHand | PJPEG |
|---|---|---|
Chrome
|
✕ |
✓ All
|
Firefox
|
✕ |
✓ All
|
Safari
|
✕ |
✓ All
|
Edge
|
✕ |
✓ All
|
IE (Legacy)
|
✕ |
✓
|
FreeHand
FreeHand Strengths
- Historically one of the most powerful and intuitive vector editors on the market, praised for multi-page support long before Adobe Illustrator implemented it
- Files are generally compact and self-contained
Limitations
- Completely abandoned proprietary format; Adobe actively blocked native import in modern versions of Illustrator
- No support in modern web browsers; must be converted to SVG
- Versioning fragmentation means parsers must account for wildly different binary structures depending on the specific .fhX extension used
PJPEG
PJPEG Strengths
- Progressive JPEGs (which this MIME type attempted to describe) provide excellent perceived loading speeds on slow connections by rendering a low-resolution preview first
- Files sent with this MIME type are fully backwards compatible with any standard JPEG decoder
Limitations
- It is a non-standard MIME type that violates IANA specifications
- Causes strict file upload validation scripts to fail if not explicitly whitelisted or mapped
- Creates unnecessary confusion, as the official image/jpeg MIME type already fully encompasses progressive encoding
When to choose which format
FreeHand
Use FreeHand when…
- Legacy Graphic Design Portfolios
- Historical Desktop Publishing Archival
- Old Corporate Logo Vectors
PJPEG
Use PJPEG when…
- Legacy Internet Explorer File Uploads
- Progressive Image Rendering (Historical context)