gzippy

The fastest gzip on any hardware. Drop-in for gzip, gunzip, gzcat, zcat, and ungzippy — same RFC 1952 output, every decompressor on Earth still reads your files.

Install

curl -fsSL https://raw.githubusercontent.com/JackDanger/gzippy/main/scripts/install.sh | bash

One line. Detects macOS, Debian, Ubuntu, and most Linux, then uses the right package manager.

macOS — Homebrew

brew tap jackdanger/gzippy https://github.com/JackDanger/gzippy
brew install jackdanger/gzippy/gzippy

Debian / Ubuntu — apt

curl -fsSL https://jackdanger.github.io/gzippy/gzippy-signing-key.asc \
    | gpg --dearmor \
    | sudo tee /etc/apt/keyrings/gzippy.gpg >/dev/null
echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/gzippy.gpg] \
    https://jackdanger.github.io/gzippy stable main" \
    | sudo tee /etc/apt/sources.list.d/gzippy.list >/dev/null
sudo apt-get update
sudo apt-get install gzippy

Replace system gzip (via dpkg-divert):

sudo apt-get install gzippy-replace-gzip

Build from source

git clone --recursive https://github.com/JackDanger/gzippy
cd gzippy && cargo build --release

How fast?

Measured on the Silesia compression corpus (202 MB of mixed text, source code, images, and database dumps), Apple M4 Pro with 14 cores, macOS 15. Level 6. Median of 15 runs per tool.

Compression (14 threads)

Decompression (single-member gzip)

Reproduce with scripts/readme_benchmark.py after cargo build --release and (cd pigz && make).

One binary, many names

gzip    gunzip    gzcat    zcat    ungzippy    gzippy

All six commands are the same Rust binary. gunzip file.gz and gzippy -d file.gz take identical code paths at identical speed. Installers put gzippy ahead of the system gzip in $PATH, so the takeover is silent — and /usr/bin/gzip stays untouched.

Beyond gzip

$ gzippy --analyze Cargo.lock
gzippy --analyze  Cargo.lock  (22.1 KB)
──────────────────────────────────────────────────────────────────────────────
  entropy    [██████▄   ]   5.22/8   MEDIUM      (mixed text and binary, or a data file)
  LZ77 cover [████████▄ ]   85.4%    EXTREME     (most bytes come for free — this file is very squishy)
  matches    2.05K  avg length 9.4 B  avg back-distance 4.8 KB
  est. gzip  [█▅        ]  ~16% of raw

  match-length histogram — how long is each reused sequence?
     3 -   4 B  ████████████████         73.0%  literal repeats; common everywhere
     9 -  16 B  █▇                        8.3%  words, variable names, small keys
    17 -  32 B  █▆                        7.7%  lines of code, struct layouts

  (canvas, colour legend, distance histogram, verdict — see `man gzippy`)

gzippy --analyze FILE prints a compression fingerprint: entropy, LZ77 coverage, an 80×20 colour canvas of the bytes, match-length and distance histograms, and a one-line verdict. No other gzip does this.

The full manual lives in man gzippy. The "GZ" parallel-block wire format and the tuning guide have their own pages: man gzippy-format, man gzippy-tuning.

Rust library API

Add to Cargo.toml:

gzippy = "0.5"

One-shot compress and decompress using all available CPUs:

let compressed = gzippy::compress(&data, 6)?;
let decompressed = gzippy::decompress(&compressed)?;

Explicit thread count or streaming I/O:

// Standard gzip — any tool can decompress
let out = gzippy::compress_with_threads(&data, 6, 1)?;

// Streaming — no intermediate allocation
let bytes_read = gzippy::compress_to_writer(reader, writer, 6)?;
let bytes_written = gzippy::decompress_to_writer(&data, &mut writer)?;

Every function routes through the same backend-selection logic as the CLI: ISA-L SIMD, libdeflate, Zopfli, and parallel multi-block — no extra configuration needed.

Note: threads > 1 at levels 0–5 produces gzippy's "GZ" multi-block format, which only gzippy can decompress. Use threads = 1 or levels 6–9 for standard gzip output readable by any tool.

See src/lib.rs or cargo doc --open for the full API.

Standing on shoulders

• pigz by Mark Adler — how to parallelize gzip
• libdeflate by Eric Biggers — fast deflate
• zlib-ng — zlib with SIMD
• rapidgzip — parallel decompression
• ISA-L by Intel — SIMD assembly

License

zlib license — same as zlib and pigz.

About

Made by Jack Danger.