@343dev/optimizt

Optimizt is a command-line tool that helps prepare images for the web.

It can compress PNG, JPEG, GIF, and SVG lossy or lossless, and create AVIF and WebP versions for raster images.

Rationale

As frontend developers, we have to care about pictures: compress PNG and JPEG, remove useless parts of SVG, create AVIF and WebP for modern browsers, and so on. One day, we got tired of using a bunch of apps for that, and created one tool that does everything we want.

Usage

Install:

npm install -g @343dev/optimizt

Optimize!

optimizt path/to/picture.jpg

Command Line Flags

• --avif — create AVIF versions of images.
• --webp — create WebP versions of images.
• -f, --force — recreate AVIF and WebP versions even if they already exist.
• -l, --lossless — optimize losslessly instead of lossily.
• -v, --verbose — show detailed output (e.g. skipped files).
• -c, --config — use a custom configuration file instead of the default.
• -o, --output — write results to the specified directory.
• -p, --prefix — add prefix to optimized file names.
• -s, --suffix — add suffix to optimized file names.
• -V, --version — display the tool version.
• -h, --help — show help message.

Usage Examples

# optimize a single image
optimizt path/to/picture.jpg

# optimize multiple images losslessly
optimizt --lossless path/to/picture.jpg path/to/another/picture.png

# recursively create AVIF and WebP versions for all images in a directory
optimizt --avif --webp path/to/directory

# recursively optimize JPEG files in the current directory
find . -iname \*.jpg -exec optimizt {} +

Differences Between Lossy and Lossless

Lossy (Default)

Provides the best balance between file size reduction and minimal visual quality loss.

Lossless (--lossless flag)

• AVIF/WebP: Uses lossless compression.
• PNG/JPEG/GIF: Maximizes image quality at the expense of larger file sizes.
• SVG: Settings are identical in both modes.

Configuration

Image processing leverages:

• sharp for JPEG, PNG, WebP, and AVIF.
• svgo for SVG.
• gifsicle for GIF.

[!NOTE] In Lossless mode for JPEG, Guetzli is used. Repeated optimization may degrade visual quality.

Default settings are defined in .optimiztrc.cjs, which includes all supported parameters. Disable any parameter by setting it to false.

When using --config path/to/.optimiztrc.cjs, the specified configuration file will be used. If no --config is provided, Optimizt searches recursively from the current directory upward for .optimiztrc.cjs. If none is found, defaults are applied.

Troubleshooting

Errors like “spawn guetzli ENOENT”.

Ensure the ignore-scripts npm option is disabled. Details: funbox/optimizt/issues/9.

Development

After cloning the repository, enable Git hooks once:

npm run enable-git-hooks

This configures Git to use the versioned hooks from the .githooks directory.

Docker

Pre-Built Image

# pull latest
docker pull 343dev/optimizt

# pull specific version
docker pull 343dev/optimizt:9.0.2

Manual Build

# clone repository
git clone https://github.com/343dev/optimizt.git
cd optimizt

# build image
docker build --tag 343dev/optimizt .

Alternatively:

# build directly from GitHub
# ignores .dockerignore (see: https://github.com/docker/cli/issues/2827)
docker build --tag 343dev/optimizt https://github.com/343dev/optimizt.git

Run Container

# mount current directory to /src in the container
docker run --rm --volume $(pwd):/src 343dev/optimizt --webp ./image.png

Integrations

Optimizt works seamlessly with:

• JetBrains IDEs
• Visual Studio Code
• Sublime Text 3
• GitHub Actions Workflow

Articles

• anuwong.com — Compress files before uploading, save tons of GBs. 🇹🇭
• Linux Format, Issue 277 (July 2021) — Optimizt is ideal for reducing the disk footprint of images without any reduction in quality.

Credits

Cute picture for the project was made by Igor Garybaldi.

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