Image MIME Reference
BMP
Windows Bitmap (Legacy Windows MIME Alias)
image/x-windows-bmp
VS
Scalable Vector Graphics
image/svg+xml
SVG
A complete technical comparison of Windows Bitmap (Legacy Windows MIME Alias) and Scalable Vector Graphics — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | BMP | SVG |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| 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
Scalable Vector Graphics
image/svg+xml
Extension
.svg.svgz
Container
XML Document
Compression
Uncompressed (Plain Text XML) / Lossless (GZIP via .svgz)
Algorithm
None (for .svg)GZIP (for .svgz)
Color Depth
Vector (Independent of bit-depth), CSS Colors (HEX, RGB, HSL, Display-P3)
Developed by
World Wide Web Consortium (W3C)
Released
2001
Magic Bytes
3C 73 76 67 (for <svg) / 3C 3F 78 6D 6C (for <?xml)
Browser Support Comparison
| Browser | BMP | SVG |
|---|---|---|
|
|
✓ 1
|
✓ All
|
|
|
✓ 1
|
✓ All
|
|
|
✓ 1
|
✓ All
|
|
|
✓ 12
|
✓ All
|
|
|
✓
|
✓
|
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
SVG
SVG Strengths
- Provides infinite resolution scalability, looking perfectly crisp on high-DPI (Retina) displays without increasing file size
- Extremely lightweight compared to raster formats for flat graphics, logos, and UI elements
- Can be manipulated dynamically via the browser's CSS and JavaScript engines (DOM integration)
Limitations
- Unsuitable for complex photographic images or photorealistic textures
- Poses critical security vulnerabilities (XSS and XML External Entity attacks) if user-uploaded SVGs are not heavily sanitized
- Rendering performance degrades significantly if the SVG contains tens of thousands of complex nodes or deeply nested paths
When to choose which format
BMP
Use BMP when…
- Legacy Windows Desktop Registry Associations
- Older Enterprise Intranet Applications
- Windows Graphics Archival
SVG
Use SVG when…
- Web Logos & UI Icons
- Responsive Web Design Elements
- Interactive Data Visualizations (D3.js)
- CSS and SMIL Web Animations