MIME Database / Compare Formats / JPEG-XS-HEIF vs JXL

JPEG-XS-HEIF vs JXL Format Comparison

JPEG-XS-HEIF

JPEG XS Image (HEIF Container)

image/jxsi

JPEG XL

image/jxl

JXL

A complete technical comparison of JPEG XS 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	JPEG-XS-HEIF	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

JPEG XS Image (HEIF Container)

image/jxsi

Extension

.jxsi.jxs.hif

Container HEIF / ISOBMFF (ISO/IEC 23008-12)

Compression Lossy (Visually Lossless) / Mathematically Lossless

Algorithm

JPEG XS (ISO/IEC 21122-1)

Color Depth 8-bit, 10-bit, 12-bit, 14-bit, 16-bit

Developed by Joint Photographic Experts Group (JPEG)

Released 2019

Magic Bytes

XX XX XX XX 66 74 79 70 6A 78 73 69

Full JPEG-XS-HEIF 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	JPEG-XS-HEIF	JXL
Chrome	✕	✕
Firefox	✕	✕
Safari	✕	✓ 17+
Edge	✕	✕
IE (Legacy)	✕	✕

JPEG-XS-HEIF

JPEG-XS-HEIF Strengths

Provides sub-millisecond encoding and decoding latency while retaining visually lossless quality
Brings the extensive metadata, EXIF, XMP, and color-profiling capabilities of the HEIF container to JPEG XS
Allows grouping of multiple high-quality JPEG XS frames into a single collection file

Limitations

Zero web browser compatibility, limiting it entirely to professional and industrial hardware workflows
Extremely niche adoption compared to standard HEVC-based HEIC or raw JPEG XS codestreams
Requires custom parsing logic to extract the JPEG XS codestream from the HEIF boxes

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