Free webp to jpg
Image MIME Reference
ACES

ACES Image Container File

image/aces
VS

JPEG XL

image/jxl
JXL

A complete technical comparison of ACES Image Container File 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 ACES JXL
Transparency (Alpha) Yes Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No Yes
HDR Support Yes Yes
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
ACES Image Container File
image/aces
Extension
.exr
Container OpenEXR (SMPTE ST 2065-4)
Compression Lossless / Uncompressed
Algorithm
PIZZIPRLEB44Uncompressed
Color Depth 16-bit (Half-float), 32-bit (Float)
Developed by Academy of Motion Picture Arts and Sciences (AMPAS) / SMPTE
Released 2013
Magic Bytes
76 2F 31 01
Full ACES 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 ACES JXL
Chrome Chrome
Firefox Firefox
Safari Safari
✓ 17+
Edge Edge
IE IE (Legacy)
ACES

ACES Strengths

  • Industry standard for high-end visual effects, compositing, and color grading
  • Supports 16-bit half-float data, accurately capturing immense dynamic range without clipping
  • Standardized by SMPTE (ST 2065-4) to guarantee universal color interoperability across different post-production facilities
Limitations
  • Considerably larger file sizes than conventional consumer image formats
  • Completely unsupported in web browsers and most standard desktop viewers
  • Requires specialized compositing or color grading software to interpret and view the scene-linear data correctly
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

ACES
Use ACES when…
  • Visual Effects (VFX)
  • Digital Intermediate (DI)
  • Color Grading
  • Archival
JXL
Use JXL when…
  • High-End Web Delivery (via Safari/Polyfills)
  • HDR Photography
  • Legacy JPEG Archiving
  • Digital Art & Image Storage
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