# kornelski/pngquant

Lossy PNG compressor — pngquant command based on libimagequant library

Repository: https://github.com/kornelski/pngquant
Canonical: https://ross.abutalabs.com/products/pngquant
Homepage: https://pngquant.org
Language: C
License: NOASSERTION
License Family: other
Topics: pngquant, quality, png, png-compression, quantization, stdin, palette, smaller, conversion, image-optimization, c
Last push: 2026-06-21T02:27:23+00:00

## Health v2 (maintenance only)
Score: 72/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 88, release rhythm 35, longevity 100
- inputs: {"age_days": 6194, "days_push": 74, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5742, forks 505 (observed 2026-08-28T04:09:28.424806+00:00)

## What it is
pngquant is a command-line lossy PNG compressor that converts images to efficient 8-bit palette PNGs with alpha support, often reducing file sizes by 60-80%. It is built on the libimagequant library (now written in Rust) and offers configurable quality levels, adaptive dithering, and fast batch processing.

## Use cases
- compress png images to smaller file sizes
- convert 24-bit pngs to 8-bit palette pngs with alpha
- batch optimize png files for the web
- reduce png file size from the command line
- shrink png images in a build pipeline or shell script
- quantize image colors while preserving transparency

## When to choose
- you need significantly smaller PNG files for web delivery while keeping alpha transparency
- you want fast batch or stdin/stdout image compression in scripts and CI
- you need a mature, standards-compliant palette quantizer with quality thresholds

## When to avoid
- you need truly lossless PNG optimization (use oxipng or zopflipng instead)
- you are compressing non-PNG formats like JPEG or WebP
- you cannot accept any lossy quality reduction in your images

## Facets
- artifact type: cli-tool
- maturity: stable
- function: image-processing, compression, cli
- domain: image-processing, web-development, graphics, files
- platform: windows, cli, cross-platform
- tags: png, lossy-compression, palette-quantization, dithering, image-optimization, alpha-transparency, libimagequant, batch-processing, linux, macos

## Member repositories
- kornelski/pngquant (main) score 72

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:28.424806+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 2026-08-29T17:53:20.859897+00:00, confidence not recorded.
  - readme: https://github.com/kornelski/pngquant (fetched 2026-08-28T04:09:28.424806+00:00, sha adfe7b845261)
  - homepage: https://pngquant.org (fetched 2026-08-29T08:48:46.631408+00:00, sha 874f7b1d58fe)
  - site_page: https://pngquant.org/install.html (fetched 2026-08-29T08:48:46.638050+00:00, sha 307e02806e56)
  - site_page: https://pngquant.org/releases.html (fetched 2026-08-29T08:48:46.635475+00:00, sha 2cdc97d12fa9)
- Data as of 2026-08-30T08:39:29.467469+00:00.