Reduce Largest Contentful Paint (RLCP)

A powerful CLI tool to optimize images in your project, convert them to modern formats (like WebP), and automatically update file references in your code.

Demo Video - Here

Usage

1. Configuration: Create a rlcp.config.json file in your project root.

   {
   	"input": "public",
   	"output": "temp_public",
   	"blacklists": ["public/brand/**"],
   	"file_size": "small",
   	"preferred_type": "webp",
   	"working_directory": "./"
   }

2. Run: Execute the tool in your project directory.

   bunx rlcp
   # or if installed locally
   bun start

Configuration (rlcp.config.json)

| Key | Type | Description | Required | | ------------------- | -------- | --------------------------------------------------------------------------- | :------: | | input | string | Directory to scan for source images. | Yes | | output | string | Directory where original images will be moved (backup). | Yes | | blacklists | array | Glob patterns for files/folders to ignore. | No | | file_size | string | Target quality: "small" (80%) or "smallest" (60%). | No | | preferred_type | string | Target format: "png", "jpeg", "jpg", or "webp". | No | | working_directory | string | Directory to scan for code files to update references (e.g., HTML, JS, TS). | No |

If optional fields are omitted, the CLI will prompt you for them during execution.

Features

🖼️ Image Conversion & Optimization

Converts images found in the input directory to your preferred format (e.g., PNG to WebP) and optimizes them based on the selected quality setting.

📦 Safe Backup

Original images are not deleted. They are moved to the specified output directory, preserving their original folder structure. This directory is automatically added to .gitignore.

🔄 Automatic Reference Updates

If working_directory is specified, Reduce Largest Contentful Paint (RLCP) scans your code files (HTML, JS, JSX, TS, TSX, CSS, JSON, MD) and automatically updates references to point to the new file extensions (e.g., changing img.png to img.webp in your index.html).

🔒 Smart Locking

Reduce Largest Contentful Paint (RLCP) creates a rlcp.lock file to track converted images.

• Prevents re-converting images that have already been processed.
• Ensures reference updates still work even if the original file has been moved to the backup folder.
• Detects if the converted file is missing and allows re-generation if needed.