Free webp to jpg
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Image MIME Reference
FITS

Flexible Image Transport System

image/fits
VS

Scalable Vector Graphics

image/svg+xml
SVG

A complete technical comparison of Flexible Image Transport System 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 FITS 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
Flexible Image Transport System
image/fits
Extension
.fits.fit.fts
Container FITS
Compression Uncompressed / Tile Compressed (Rice, GZIP)
Algorithm
UncompressedRiceGZIPHcompress
Color Depth 8-bit, 16-bit, 32-bit, 64-bit (Float/Double)
Developed by IAU FITS Working Group / NASA
Released 1981
Magic Bytes
53 49 4D 50 4C 45 20 20 3D 20
Full FITS 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 FITS SVG
Chrome Chrome
✕
✓ All
Firefox Firefox
✕
✓ All
Safari Safari
✕
✓ All
Edge Edge
✕
✓ All
IE IE (Legacy)
✕
✓
FITS

FITS Strengths

  • The undisputed global standard for archiving and sharing astronomical data
  • Self-documenting: Headers are written in plain ASCII, ensuring data is readable decades later regardless of software
  • Supports incredibly high dynamic range, N-dimensional arrays, and complex binary tables
Limitations
  • No support in standard consumer software or web browsers
  • Uncompressed raw FITS files from modern telescopes can be excessively large
  • Does not use standard metadata models like EXIF or XMP, requiring specialized parsers
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

FITS
Use FITS when…
  • Astronomy & Astrophysics
  • Space Telescope Data (Hubble, JWST)
  • Scientific Data Archiving
  • Spectroscopy
SVG
Use SVG when…
  • Web Logos & UI Icons
  • Responsive Web Design Elements
  • Interactive Data Visualizations (D3.js)
  • CSS and SMIL Web Animations

More comparisons

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