# lz4/lz4

Extremely Fast Compression algorithm

Repository: https://github.com/lz4/lz4
Canonical: https://ross.abutalabs.com/products/lz4
Homepage: http://www.lz4.org
Language: C
License: NOASSERTION
License Family: other
Topics: lz4, c, compression
Last push: 2026-07-01T06:42:40+00:00

## Health v2 (maintenance only)
Score: 63/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 90, release rhythm 8, longevity 100
- inputs: {"age_days": 4544, "days_push": 63, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 12034, forks 1582 (observed 2026-08-28T04:10:51.445200+00:00)

## What it is
LZ4 is a lossless compression algorithm and C library focused on extremely fast compression and decompression speeds, with a high-compression LZ4_HC variant and dictionary compression support. It also ships a command-line tool and bindings for many languages.

## Use cases
- compress data at very high speed
- fast decompression of game assets or kernel images
- compress small files with a trained dictionary
- reduce storage footprint with minimal CPU overhead
- embed a lightweight compression codec in C or other languages

## When to choose
- speed matters more than compression ratio
- you need multi-GB/s decompression near RAM speed
- you want a tiny, portable, dependency-free C library
- compressing small data where dictionary compression helps

## When to avoid
- you need maximum compression ratio rather than speed
- you need built-in encryption or archival features like tar/zip
- you prefer a single modern format like zstd with richer features

## Facets
- artifact type: library
- maturity: stable
- function: compression, cli
- domain: developer-tools, files, performance
- platform: cross-platform, c, cli
- tags: lossless-compression, lz77, high-performance, dictionary-compression

## Member repositories
- lz4/lz4 (main) score 63

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:51.445200+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 2026-08-29T17:14:59.569827+00:00, confidence not recorded.
  - readme: https://github.com/lz4/lz4 (fetched 2026-08-28T04:10:51.445200+00:00, sha 6d3ea6404c84)
  - homepage: http://www.lz4.org (fetched 2026-08-29T08:12:34.290710+00:00, sha 59cb7e4d1b64)
- Data as of 2026-08-30T08:39:29.467469+00:00.