Install guetzli with Homebrew

Project links

• Homepage

Commands and aliases

• guetzli

Project history

Google announced Guetzli as open source on 2017-03-16. The announcement described it as a JPEG encoder for digital images and web graphics that targeted file-size reductions while remaining compatible with existing browsers, image-processing applications, and the JPEG standard.

The repository README says Guetzli-generated images are typically 20-30 percent smaller than libjpeg images of equivalent quality, and that Guetzli emits sequential, non-progressive JPEGs. The implementation uses a psychovisual approach focused on quantization decisions, with Butteraugli-related perceptual modeling present in the repository.

Adoption history

Guetzli was quickly packaged because it offered an easy experiment for web image optimization: a single CLI that reads PNG or JPEG input and writes optimized JPEG output. The official README documents Homebrew and MacPorts installation paths, and the input metadata records packaging across Alpine, Homebrew, Debian, MacPorts, Nix, Arch, Scoop, and Ubuntu.

Its adoption was bounded by cost. The README warns that it uses about 300 MB of memory per megapixel and roughly one minute of CPU per megapixel, making it better suited to offline asset pipelines than interactive image conversion.

How it is used

The CLI usage is direct: `guetzli [--quality Q] [--verbose] original.png output.jpg` or the same with JPEG input. The README recommends high-quality, preferably uncompressed input and notes that PNG alpha is flattened onto black because JPEG has no alpha channel.

Guetzli assumes sRGB input with gamma 2.2 and ignores color-profile metadata. That assumption is important in package notes because it affects whether the tool is appropriate for a given image workflow.

Why package nerds care

Guetzli is a package-nerd favorite because it embodies a clear tradeoff: excellent density for legacy JPEGs, paid for with CPU and memory. It is a compact command-line artifact from a major research organization, easy to package, easy to benchmark, and easy to compare against libjpeg, MozJPEG, Zopfli, WebP, JPEG XL, and later Jpegli work.

Google's later Jpegli announcement explicitly places newer JPEG work in relation to earlier Guetzli-style heuristics, making Guetzli part of the historical path from high-effort JPEG optimization toward faster modern JPEG-compatible encoders.

Timeline

• 2017-03-16: Google Open Source Blog announces Guetzli.
• 2017-03-21: GitHub release metadata shows the release series around the public launch window.
• 2017: README documents POSIX, Windows, macOS, Homebrew, MacPorts, and Bazel build paths.
• 2024: Google's Jpegli announcement discusses faster heuristics developed after earlier Guetzli-style approaches.

Related projects

• Guetzli is related to libjpeg, MozJPEG, Butteraugli, Zopfli, WebP, JPEG XL, Brunsli, and Jpegli. Its distinguishing trait is staying inside the legacy JPEG format while using a slower perceptual search to improve compression density.

Sources

• https://github.com/google/guetzli
• https://opensource.googleblog.com/2017/03/guetzli-new-open-source-jpeg-encoder.html
• https://opensource.googleblog.com/2024/04/introducing-jpegli-new-jpeg-coding-library.html
• https://raw.githubusercontent.com/google/guetzli/master/README.md