Free webp to jpg
EN
Image MIME Reference
AVCI

AVC Image (HEIF Container)

image/avci
VS

JPEG XL

image/jxl
JXL

A complete technical comparison of AVC Image (HEIF Container) 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 AVCI JXL
Transparency (Alpha) Yes Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No Yes
HDR Support Yes Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
AVC Image (HEIF Container)
image/avci
Extension
.avci.hif
Container HEIF / ISOBMFF (ISO/IEC 14496-12)
Compression Lossy / Lossless
Algorithm
AVC (Advanced Video Coding / H.264)
Color Depth 8-bit, 10-bit, 12-bit
Developed by Moving Picture Experts Group (MPEG) / ISO/IEC JTC 1
Released 2015
Magic Bytes
XX XX XX XX 66 74 79 70 61 76 63 69
Full AVCI 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 AVCI JXL
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕
✓ 17+
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
AVCI

AVCI Strengths

  • Shares the robust, flexible HEIF container architecture that allows for rich metadata, HDR, and depth maps.
  • Backed by the highly ubiquitous AVC (H.264) codec, which is widely supported in hardware decoding.
  • Supports rectangular cropping and rotation metadata without needing to re-encode the pixel data.
Limitations
  • No native support within web browsers for HTML rendering.
  • Inferior compression efficiency when compared to newer container formats like HEIC (HEVC) or AVIF (AV1).
  • Easily confused with HEIC and AVIF, which use the same base ISOBMFF container.
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

AVCI
Use AVCI when…
  • Digital Photography
  • Camera Capture
  • Archival Storage
JXL
Use JXL when…
  • High-End Web Delivery (via Safari/Polyfills)
  • HDR Photography
  • Legacy JPEG Archiving
  • Digital Art & Image Storage

More comparisons

AVCI vs ACES → JXL vs ACES → AVCI vs APNG → JXL vs APNG → AVCI vs AVCS → JXL vs AVCS → AVCI vs AVIF → JXL vs AVIF → All comparisons →
Share this comparison