System - Automatic WebP & Image Resizer for Joomla 4/5

This Joomla system plugin is designed to solve the "heavy image" problem automatically. It ensures that no matter how large an image a user uploads, the website visitor only receives a modern, compressed, and correctly sized version.

🚀 Key Features

• Auto-Resize: Detects images wider than 1280px and scales them down to fit web standards while maintaining aspect ratio.
• WebP Conversion: Automatically generates a .webp version of any .jpg, .jpeg, or .png file found in the article content.
• On-the-Fly Processing: If a WebP version doesn't exist, the plugin creates it the moment the page is loaded.
• Non-Destructive: It never deletes your original images. It creates a companion .webp file, keeping your high-res originals safe.
• Smart Caching: Uses the Joomla Output Cache to store processed HTML, ensuring zero impact on server performance after the initial conversion.
• Gallery Compatible: Works perfectly with "Simple Image Gallery" and other content plugins by intercepting their output.

🛠 Installation

1. Download or create the webpconverter.zip containing webpconverter.php and webpconverter.xml.
2. In your Joomla Backend, go to System → Install → Extensions.
3. Upload the .zip file.
4. Navigate to System → Plugins, search for "System - Automatic WebP & Image Resizer" and set the status to Enabled.

⚙️ How it Works

The plugin follows a specific logic flow to ensure maximum speed and compatibility:

1. Intercepts HTML: Before the page is sent to the user, the plugin scans for <img> tags.
2. Checks File System: It looks for a .webp version of each image.
3. Processes (if needed):

• If no WebP exists, it loads the original.
• If the original is > 1280px wide, it resizes it.
• It saves the new file as a .webp.

4. Rewrites URLs: It changes <img src="photo.jpg"> to <img src="photo.webp"> in the code.
5. Caches: The final HTML is cached so the next visitor gets the result instantly.

📋 Requirements

• Joomla: 4.x or 5.x
• PHP: 7.4 or 8.x
• PHP Extensions: GD Library with WebP support (standard on most hosts).
• Permissions: Your images/ folder must be writable (755).

⚠️ Important Notes

• First Load: The very first time you visit a page with many new images, it may take a few seconds to generate the files. Subsequent loads will be instant.
• Media Manager: You will see both the original file and a .webp version in your Media Manager. This is normal.
• Transparency: PNG transparency is preserved during the conversion process.