Image MIME Reference
RealFlash
RealNetworks RealFlash
image/vnd.rn-realflash
VS
Extended Image File Format
image/vnd.xiff
XIFF
A complete technical comparison of RealNetworks RealFlash 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 | RealFlash | XIFF |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
RealNetworks RealFlash
image/vnd.rn-realflash
Extension
Container
RealMedia / SWF
Compression
Vector (Flash) / RealAudio Compression
Algorithm
Macromedia Vector CompressionDeflate (Zlib)
Color Depth
8-bit, 24-bit, 32-bit
Developed by
RealNetworks & Macromedia
Released
1997
Magic Bytes
46 57 53 (FWS - Standard Flash) or 2E 52 4D 46 (.RMF - RealMedia Container)
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
Browser Support Comparison
| Browser | RealFlash | XIFF |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
RealFlash
RealFlash Strengths
- Allowed complex, interactive vector animations to stream smoothly over 28.8k dial-up modems
- Perfectly synchronized streaming audio with timeline-based animations, which was revolutionary in 1997
Limitations
- Heavily reliant on proprietary browser plugins (RealPlayer), which were notoriously bloated
- Completely obsolete and unsupported on the modern web
- Tightly coupled server-client architecture required expensive RealServer licenses to host
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
RealFlash
Use RealFlash when…
- Historical Dial-up Web Animation
- Late-1990s Interactive Music Videos
- Streaming Vector Graphics
XIFF
Use XIFF when…
- Keyfile Enterprise Document Management
- Legacy Corporate Workflow Archival
- Scanned Multi-page Document Routing