# libjxl/libjxl

JPEG XL image format reference implementation

Repository: https://github.com/libjxl/libjxl
Canonical: https://ross.abutalabs.com/products/libjxl
Language: C++
License: BSD-3-Clause
License Family: permissive
Topics: image-compression, encoder, decoder, codec, lossless-compression-algorithm, lossy-compression, lossy-image-compression, lossy, lossless-image-compression, lossless-images, photography, photos, images, jpeg, jpeg-xl, jxl
Last push: 2026-08-26T14:20:24+00:00

## Health v2 (maintenance only)
Score: 96/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 91, longevity 100
- inputs: {"age_days": 2022, "days_push": 7, "days_rel": 63, "gap_med": 0, "n_releases_24m": 12}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3637, forks 386 (observed 2026-08-28T04:08:12.744540+00:00)

## What it is
libjxl is the reference implementation of the JPEG XL (ISO/IEC 18181) image format, providing both an encoder (cjxl) and decoder (djxl) as a C++ library and command-line tools. It supports lossy and lossless compression of images and is integrated into many applications that support JPEG XL.

## Use cases
- convert images to jpeg xl format
- decode jxl files
- compress photos losslessly
- batch transcode jpeg to jpeg xl
- integrate jpeg xl support into an application
- benchmark image codecs

## When to choose
- you need standards-compliant JPEG XL encoding or decoding
- you want better compression than JPEG/WebP/AVIF for images
- you need lossless image compression with good ratios
- you are building an image viewer or editor with JXL support

## When to avoid
- you need broad ecosystem support for older browsers or legacy software
- you need a stable, frozen API - the library API and CLI options are still subject to change
- you only need simple PNG/JPEG handling without new formats

## Facets
- artifact type: library
- maturity: active
- function: image-processing, compression
- domain: image-processing, photography, files
- platform: windows, cpp, cli, cross-platform
- tags: jpeg-xl, jxl, encoder, decoder, codec, lossless-compression, lossy-compression, reference-implementation, linux, macos

## Member repositories
- libjxl/libjxl (main) score 96

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:12.744540+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:31:49.803047+00:00, confidence not recorded.
  - readme: https://github.com/libjxl/libjxl (fetched 2026-08-28T04:08:12.744540+00:00, sha ff60798443b2)
- Data as of 2026-08-30T08:39:29.467469+00:00.