Free webp to jpg
Image MIME Reference
BMP

Windows Bitmap (Legacy Windows MIME Alias)

image/x-windows-bmp
VS

Wireless Bitmap

image/vnd.wap.wbmp
WBMP

A complete technical comparison of Windows Bitmap (Legacy Windows MIME Alias) and Wireless Bitmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

BMP wins on browser support

Feature Support

Feature BMP WBMP
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile Yes ✕ No
Windows Bitmap (Legacy Windows MIME Alias)
image/x-windows-bmp
Extension
.bmp.dib
Container DIB (Device-Independent Bitmap)
Compression Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneRLE4RLE8
Color Depth 1-bit (Monochrome), 4-bit (16 colors), 8-bit (256 colors), 16-bit (High Color), 24-bit (True Color), 32-bit (True Color with Alpha)
Developed by Microsoft Corporation
Released 1985
Magic Bytes
42 4D
Full BMP reference →
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
Full WBMP reference →

Browser Support Comparison

Browser BMP WBMP
Chrome Chrome
✓ 1
Firefox Firefox
✓ 1
Safari Safari
✓ 1
Edge Edge
✓ 12
IE IE (Legacy)
BMP

BMP Strengths

  • Universally supported by all major operating systems and modern web browsers
  • Maintains perfect, lossless fidelity because pixel data is stored without lossy compression artifacts
Limitations
  • Massive file size overhead due to a lack of modern compression algorithms
  • Legacy MIME strings like 'image/x-windows-bmp' can trigger validation warnings in strict security or API environments if unhandled
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

BMP
Use BMP when…
  • Legacy Windows Desktop Registry Associations
  • Older Enterprise Intranet Applications
  • Windows Graphics Archival
WBMP
Use WBMP when…
  • Legacy WML (Wireless Markup Language) Mobile Sites
  • Early Mobile Phone Icons and Operator Logos
  • Historical WAP Archival
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