Optimize Images Action

A fast GitHub Action powered by Bun and native Bun.Image processing pipeline to automatically optimize JPEG, PNG, and WebP images in your GitHub repository.

Features

• Blazing Fast: Powered by Bun's native image transformation pipeline (zero heavy C++ native module npm installs).
• Supports Popular Formats: Optimizes .jpg, .jpeg, .png, and .webp images.
• Optional WebP Conversion: Optionally converts JPEG/PNG images to modern WebP format when byte savings are realized.
• Configurable: Customize compression levels, target folders, and ignored patterns.
• Detailed Output: Provides clear logs and GitHub Action output variables for summary reports and downstream steps.

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Usage

Add a workflow file (e.g. .github/workflows/optimize-images.yml) to your repository:

Basic Example (Automated PR / Push Optimization)

name: Optimize Images

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  optimize:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Optimize Images
        uses: ./
        with:
          jpeg_quality: "80"
          png_compression_level: "6"
          webp_quality: "80"

      - name: Commit optimized images
        uses: stefanzweifel/git-auto-commit-action@v5
        with:
          commit_message: "chore: optimize images [skip ci]"

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Inputs

Input	Description	Default
path	Target directory or path pattern to search for images.	.
ignore_paths	Comma-separated list of relative directory/file paths to ignore.	node_modules,.git,dist,build
jpeg_quality	Compression quality for JPEG images (1-100).	80
png_compression_level	Compression level for PNG images (0-9).	6
webp_quality	Compression quality for WebP images (1-100).	80
convert_to_webp	Automatically convert JPEG/PNG images to WebP format if size decreases (true/false).	false

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Outputs

Output	Description
total_original_bytes	Total byte size of all discovered target images before optimization.
total_optimized_bytes	Total byte size of images after optimization.
total_saved_bytes	Total bytes saved across all optimized images.
optimized_count	Number of images successfully optimized or converted.

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Local Development & Testing

Run tests locally using Bun:

bun test

Run the optimizer on local images:

INPUT_PATH="./images" bun run src/index.ts

License

MIT