Free webp to jpg
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Image MIME Reference
IEF

Image Exchange Format

image/ief
VS

JPEG XL

image/jxl
JXL

A complete technical comparison of Image Exchange Format and JPEG XL — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

JXL wins on browser support

Feature Support

Feature IEF JXL
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No Yes
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
Image Exchange Format
image/ief
Extension
.ief
Container TIFF Class B (TIFF-B)
Compression Lossless (MH, MR, MMR) / Uncompressed
Algorithm
MHMRMMRUncompressed
Color Depth 1-bit (Monochrome)
Developed by IETF Network Fax Working Group
Released 1992
Magic Bytes
49 49 2A 00 (Little-endian) / 4D 4D 00 2A (Big-endian)
Full IEF reference →
JPEG XL
image/jxl
Extension
.jxl
Container ISOBMFF / JPEG XL Codestream
Compression Lossy (VarDCT) / Lossless (Modular)
Algorithm
VarDCT (Variable block-size DCT)Modular (Predictive coding for lossless)
Color Depth 8-bit, 10-bit, 12-bit, 16-bit, 32-bit (Float)
Developed by Joint Photographic Experts Group (JPEG)
Released 2021
Magic Bytes
FF 0A (Codestream) / 00 00 00 0C 4A 58 4C 20 0D 0A 87 0A (Container)
Full JXL reference →

Browser Support Comparison

Browser IEF JXL
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕
✓ 17+
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
IEF

IEF Strengths

  • Provided a standard method for exchanging bi-level fax images during the early days of the Internet
  • Supported multi-page documents
  • Leveraged the highly resilient and well-documented TIFF container
Limitations
  • Completely obsolete and unsupported in modern computing environments
  • Strictly limited to 1-bit monochrome data, lacking color or grayscale capabilities
  • Magic bytes overlap completely with standard TIFF, making specific filetype detection difficult without parsing internal tags
JXL

JXL Strengths

  • Capable of losslessly recompressing legacy JPEG files, saving ~20% space while retaining perfect byte-for-byte restorability
  • Highly superior progressive decoding (Saliency-driven), allowing recognizable images to load extremely fast on slow connections
  • Outperforms WebP and competes favorably with AVIF, especially at high-fidelity settings and for complex textures/photography
  • Royalty-free with an open-source reference implementation (libjxl)
Limitations
  • Google's removal of JXL support from Chrome severely hindered its adoption as a universal web standard
  • Lack of hardware decoding chips compared to video-derived codecs like AVIF (AV1)
  • File parsing logic is complex due to the split between raw codestreams and ISOBMFF containers

When to choose which format

IEF
Use IEF when…
  • Legacy Fax Transmissions
  • Early Internet Gateways
  • Archival
JXL
Use JXL when…
  • High-End Web Delivery (via Safari/Polyfills)
  • HDR Photography
  • Legacy JPEG Archiving
  • Digital Art & Image Storage

More comparisons

IEF vs ACES → JXL vs ACES → IEF vs APNG → JXL vs APNG → IEF vs AVCI → JXL vs AVCI → IEF vs AVCS → JXL vs AVCS → IEF vs AVIF → JXL vs AVIF → All comparisons →
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