Image MIME Reference
PCX
PiCture eXchange
image/x-pcx
VS
Wireless Bitmap
image/vnd.wap.wbmp
WBMP
A complete technical comparison of PiCture eXchange and Wireless Bitmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | PCX | WBMP |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
PiCture eXchange
image/x-pcx
Extension
.pcx
Container
ZSoft Proprietary Header (128 bytes)
Compression
Run-Length Encoding (RLE)
Algorithm
ZSoft RLE
Color Depth
1-bit (Monochrome), 4-bit (16 colors), 8-bit (256 colors), 24-bit (True Color)
Developed by
ZSoft Corporation
Released
1985
Magic Bytes
0A (followed by version, e.g., 0A 05 01 08)
Wireless Bitmap
image/vnd.wap.wbmp
Extension
.wbmp
Container
WBMP Type 0
Compression
Uncompressed
Algorithm
None
Color Depth
1-bit (Monochrome)
Developed by
WAP Forum (Now Open Mobile Alliance)
Released
1999
Magic Bytes
00 00
Browser Support Comparison
| Browser | PCX | WBMP |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
PCX
PCX Strengths
- Incredibly simple RLE algorithm makes it very fast to decode, which was historically vital for early 3D video game engines
- Retains crisp, lossless pixel data suitable for pixel art and interface assets
- Well-documented and highly supported by older desktop publishing and image editing software
Limitations
- Extremely inefficient compression by modern standards, producing large file sizes compared to PNG
- Lacks modern imaging features such as alpha channel transparency, EXIF metadata, and color profiles
- Zero support in web browsers; must be converted to PNG for web use
WBMP
WBMP Strengths
- Extremely low processing overhead made it perfectly suited for the ultra-low-power CPUs of late 1990s mobile devices
- Tightly integrated into the WML (Wireless Markup Language) stack, enabling the first functional mobile internet experiences
Limitations
- Completely obsolete and lacks support in modern operating systems and browsers
- Limited entirely to 1-bit black and white (0 for black, 1 for white) with zero support for grayscale, color, or transparency
- The lack of a strong file header signature makes automated MIME type detection highly unreliable
When to choose which format
PCX
Use PCX when…
- MS-DOS and Early Windows Graphics
- 1990s Video Game Assets (Textures, UI)
- Retro Computing Archival
WBMP
Use WBMP when…
- Legacy WML (Wireless Markup Language) Mobile Sites
- Early Mobile Phone Icons and Operator Logos
- Historical WAP Archival