Free webp to jpg
EN
Image MIME Reference
PGM

Portable Graymap

image/x-portable-graymap
VS

Scalable Vector Graphics

image/svg+xml
SVG

A complete technical comparison of Portable Graymap and Scalable Vector Graphics — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

SVG wins on browser support

Feature Support

Feature PGM SVG
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No ✕ No
HDR Support Yes Yes
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No ✕ No
Portable Graymap
image/x-portable-graymap
Extension
.pgm
Container Netpbm
Compression Uncompressed
Algorithm
None
Color Depth 8-bit (Grayscale), 16-bit (Grayscale)
Developed by Jef Poskanzer (Netpbm Project)
Released 1988
Magic Bytes
50 32 (ASCII) or 50 35 (Binary)
Full PGM reference →
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)
Full SVG reference →

Browser Support Comparison

Browser PGM SVG
Chrome Chrome
✕
✓ All
Firefox Firefox
✕
✓ All
Safari Safari
✕
✓ All
Edge Edge
✕
✓ All
IE IE (Legacy)
✕
✓
PGM

PGM Strengths

  • Extremely simple format allows custom parsers to be written from scratch in minimal time
  • Supports 16-bit precision, making it highly valuable for scientific, medical, and height-map data where 8-bit precision is insufficient
  • ASCII encoding ('P2') allows manual editing and visual inspection of pixel values directly within a text editor
Limitations
  • Strictly limited to grayscale; cannot display color
  • Lack of compression results in massive file sizes, making it entirely impractical for web delivery or consumer storage
  • Does not support alpha transparency or modern metadata structures
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

PGM
Use PGM when…
  • Computer Vision and Machine Learning Pre-processing
  • Scientific and Medical Image Processing
  • Unix/Linux Command-Line Image Pipelines
SVG
Use SVG when…
  • Web Logos & UI Icons
  • Responsive Web Design Elements
  • Interactive Data Visualizations (D3.js)
  • CSS and SMIL Web Animations

More comparisons

PGM vs ACES → SVG vs ACES → PGM vs APNG → SVG vs APNG → PGM vs AVCI → SVG vs AVCI → PGM vs AVCS → SVG vs AVCS → PGM vs AVIF → SVG vs AVIF → All comparisons →
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