How to convert Images to WEBP in Robin Image Optimizer

This article explains how to convert images to WebP format using the Robin Image Optimizer plugin. It covers settings configuration, bulk conversion, and converting a single image from the Media Library.

Overview

Robin Image Optimizer converts images to WebP directly on your server. All optimized and converted images remain on your hosting environment. The plugin does not use cloud-based optimization.

Before you start

Make sure the following requirements are met:

• Robin Image Optimizer is installed and activated
• Your server supports WebP image generation
• Image backups are enabled if you want the option to restore originals

Step 1: Configure WebP settings

1. Go to WordPress Dashboard > Robin Image Optimizer > Settings
2. Under Compression mode, choose your preferred option. Lossless is recommended if you want no visible quality change
3. Make sure Backup images is enabled.
4. Under Image Format Conversion, select WebP.

Choose a WebP delivery method

Select how WebP images should be delivered on the front end:

• Replace  <img> tags with <picture> tag

  Recommended if your server does not support .htaccess redirects

• Redirection via .htaccess

  Recommended for Apache servers with WebP support enabled

Save the settings once done.

Step 2: Bulk convert images to WebP

1. Go to Robin Image Optimizer > Bulk Optimization
2. Select the Media Library tab
3. Click Convert to WebP
4. Monitor progress from the dashboard

The dashboard displays pending images, converted images, and overall savings.

Step 3: Convert a single image to WebP

1. Go to Media > Library
2. Click the image you want to convert
3. In the attachment details panel, find the Image Optimizer section
4. Click Convert to WebP

The WebP version will be generated and served on the front end based on your delivery settings.

Verify WebP delivery

After conversion:

• Open the page on the front end where your images are present.
• Inspect the image using browser developer tool - Network log
• Confirm the image is served as image/webp

Important notes

• Original images are not replaced or deleted
• Additional image sizes usually come from your theme or other plugins
• You can restore original images anytime using Restore under Manage backups

Troubleshooting

If WebP images are not loading:

• Recheck the selected delivery method
• Clear all caches including CDN and browser cache
• Verify WebP support on your server

This ensures WebP images are generated and served correctly without affecting existing image URLs.