Free webp to jpg
EN
Image MIME Reference
ICO

Windows Icon (Legacy MIME)

image/x-icon
VS

JPEG Stereo Image

image/x-jps
JPS

A complete technical comparison of Windows Icon (Legacy MIME) and JPEG Stereo Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

ICO wins on browser support

Feature Support

Feature ICO JPS
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No Yes
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
Windows Icon (Legacy MIME)
image/x-icon
Extension
.ico
Container ICO Directory Structure
Compression Uncompressed (DIB/BMP) / Deflate (Embedded PNG)
Algorithm
NoneDeflate (via PNG)
Color Depth 1-bit, 4-bit, 8-bit, 24-bit (True Color), 32-bit (RGBA)
Developed by Microsoft Corporation
Released 1985
Magic Bytes
00 00 01 00
Full ICO reference →
JPEG Stereo Image
image/x-jps
Extension
.jps
Container JPEG (JFIF/Exif)
Compression Lossy (JPEG/DCT)
Algorithm
JPEG (Discrete Cosine Transform)
Color Depth 8-bit (Grayscale), 24-bit (RGB)
Developed by Stereoscopic Community (Unofficial Standard)
Released 1990
Magic Bytes
FF D8 FF
Full JPS reference →

Browser Support Comparison

Browser ICO JPS
Chrome Chrome
✓ 1
✓ 1
Firefox Firefox
✓ 1
✓ 1
Safari Safari
✓ 1
✓ 1
Edge Edge
✓ 12
✓ 12
IE IE (Legacy)
✓
✓
ICO

ICO Strengths

  • Universally supported by every web browser in existence for website favicons
  • Packs multiple resolutions into a single file, eliminating the need to serve different files for the taskbar vs. the desktop
  • Modern support for embedded PNGs (since Windows Vista) allows for excellent 32-bit transparency (alpha channels) and drastically reduced file sizes
Limitations
  • Internal file structure is convoluted due to decades of legacy cruft, such as the requirement for BMP data to lack a standard file header but double the height property for an archaic XOR/AND mask
  • Larger file size compared to a single optimized PNG or SVG, as it literally stores the same image multiple times at different scales
  • The MIME type landscape is highly fragmented (x-icon vs. vnd.microsoft.icon), causing occasional caching or strict-MIME validation errors on restrictive servers
JPS

JPS Strengths

  • 100% backward compatible with every standard 2D image viewer and web browser (which simply display the two halves side-by-side)
  • Inherits JPEG's excellent lossy compression, resulting in small file sizes ideal for web transmission
  • Extremely easy to generate programmatically by simply stitching two JPEG images side-by-side onto a wider canvas
Limitations
  • Lack of a dedicated metadata standard means viewing software has to guess whether the layout is 'cross-eyed' (right eye left, left eye right) or 'parallel' (left eye left, right eye right), occasionally causing inverted depth
  • Suffers from JPEG compression artifacts, which can break the stereoscopic illusion if compression noise differs between the left and right eyes
  • Superseded in consumer electronics by the MPO (Multi-Picture Object) format, which stacks separate full-resolution JPEGs rather than squishing them side-by-side

When to choose which format

ICO
Use ICO when…
  • Website Favicons (favicon.ico)
  • Windows Application Executable Icons (.exe)
  • Desktop Shortcut Icons
JPS
Use JPS when…
  • Stereoscopic 3D Photography
  • Virtual Reality (VR) Image Galleries
  • Cross-eye / Parallel Stereograms

More comparisons

ICO vs ACES → JPS vs ACES → ICO vs APNG → JPS vs APNG → ICO vs AVCI → JPS vs AVCI → ICO vs AVCS → JPS vs AVCS → ICO vs AVIF → JPS vs AVIF → All comparisons →
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