Free webp to jpg
Image MIME Reference
Net-FPX

Network FlashPix

image/vnd.net-fpx
VS

X Pixmap

image/x-xpixmap
XPM

A complete technical comparison of Network FlashPix and X Pixmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Net-FPX XPM
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
Network FlashPix
image/vnd.net-fpx
Extension
.fpx
Container Microsoft OLE Structured Storage (COM)
Compression JPEG (Lossy) / Uncompressed / Single-color (Solid)
Algorithm
JPEGNone
Color Depth 8-bit (Grayscale/Indexed), 24-bit (RGB), 32-bit (CMYK/RGBA)
Developed by Digital Imaging Group (Kodak, HP, Live Picture, Microsoft)
Released 1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
Full Net-FPX reference →
X Pixmap
image/x-xpixmap
Extension
.xpm
Container C Source Code Header (.c / .h)
Compression Uncompressed (Source Code)
Algorithm
None
Color Depth Indexed Color (Custom Palette with RGB and Alpha 'None')
Developed by Daniel Dardailler and Colas Nahaboo (Bull / X Consortium)
Released 1989
Magic Bytes
2F 2A 20 58 50 4D 20 2A 2F (ASCII '/* XPM */')
Full XPM reference →

Browser Support Comparison

Browser Net-FPX XPM
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
Net-FPX

Net-FPX Strengths

  • Revolutionized web imaging in the late 1990s by proving that massive gigapixel images could be navigated seamlessly over 56k dial-up modems
  • Pioneered the tile-based, multi-resolution pyramid concepts that eventually evolved into modern standards like IIIF (International Image Interoperability Framework)
Limitations
  • Completely obsolete, having been replaced by standard JPEG servers and modern tiling formats like Deep Zoom or JPEG 2000/XR
  • Relied on proprietary Java applets or ActiveX controls to render the tiles dynamically in a web browser
  • Extremely complex to parse server-side due to the heavy OLE filesystem container
XPM

XPM Strengths

  • Can be compiled directly into C or C++ source code without requiring an external asset loading mechanism
  • Human-readable palette mapping allows developers to inspect, modify, or hand-craft icons directly within a text editor
  • Native support for color palettes and transparency via the 'None' keyword
Limitations
  • Extremely inefficient storage structure for large images, resulting in massive file bloat compared to binary formats like PNG
  • Completely obsolete and unsupported in modern web browsers
  • Parsing overhead requires compiling or interpreting text-based color tables at runtime

When to choose which format

Net-FPX
Use Net-FPX when…
  • Historical Internet Imaging Protocol (IIP) Streaming
  • Early E-Commerce Deep Zoom Implementations
  • Legacy High-Resolution Image Servers
XPM
Use XPM when…
  • X Window System (X11) Application Icons and Cursors
  • Embedded C/C++ Firmware Color UI Assets
  • Early Linux Desktop Environment Themes
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