Smart Image Size Optimiser - a complete, WordPress-standards-compliant plugin.

Why This Plugin Exists

WordPress automatically generates thumbnail, medium, and large versions of every uploaded image based on dimensions set in Settings > Media. However, these are global settings that rarely align with your theme's actual requirements.

Most users either leave the WordPress defaults unchanged or guess at appropriate values, resulting in unnecessarily large file sizes, poor image quality from upscaling, or wasted server space from unused image variations.

Different themes have different layout requirements – a portfolio theme might need 1200px wide images whilst a blog theme works perfectly with 800px.

Smart Image Size Optimiser solves this by intelligently analysing your active theme to discover what dimensions are actually being used, then recommending optimal settings tailored specifically to your site.

It's a fundamental optimisation that should happen on every WordPress installation, yet somehow didn't exist until now.

Here's what it does...

✅ Scans comprehensively:

• theme.json layout settings (contentSize and wideSize for block themes)
• Active theme PHP files (for the_post_thumbnail(), add_image_size(), etc.)
• Active theme CSS files (for width/height declarations)
• Child theme files (if present)
• FSE Custom CSS from the database

✅ Smart categorisation:

• Groups sizes into Thumbnail/Medium/Large based on dimensions
• Counts frequency of each size
• Sorts by most commonly used
• Shows sources where each size was found

✅ User-friendly interface:

• Clean admin page under Settings > Image Size Optimiser
• "Scan Theme" button to initiate scanning
• Radio buttons for easy selection
• Shows current WordPress media settings for reference
• Success message with link to Regenerate Thumbnails plugin

✅ WordPress standards:

• Proper escaping (esc_html, esc_attr, esc_url)
• Nonce verification for security
• Capability checks (manage_options)
• Proper WordPress coding standards (tabs, spacing, etc.)
• EN-GB spelling throughout (Optimiser, not Optimizer!)
• Internationalisation ready

✅ Includes disclaimers:

• Warns that it can't catch everything
• Reminds users to regenerate thumbnails after updating