Thumbnail Manager

Thumbnail Manager is a powerful tool to take full control over your WordPress image system. Instead of letting themes and plugins generate dozens of unnecessary thumbnails, you can now:

• Control which sizes are created
• Remove unused thumbnails safely
• Regenerate only what you actually need

All in one place. 🚀 What it does 1. Regenerate Thumbnails (NEW)

• Regenerate thumbnails based on your current enabled sizes
• Works in batches with progress tracking (no timeout issues)
• Perfect after disabling unwanted sizes
• Ensures your Media Library stays consistent and optimized 2. Prune Unused Thumbnails
• Select sizes you want to KEEP
• Automatically detect and remove all other generated thumbnails
• Supports:
• Registered sizes
• Orphan -WxH files
• .webp, .bak, @2x, -1 variants 3. Orphan File Discovery
• Detect leftover thumbnails no longer registered
• Clean legacy sizes from old themes/plugins
• Optional aggressive cleanup mode 4. Disable Sizes for Future Uploads
• Prevent unnecessary thumbnails from being generated
• Reduce storage usage going forward
• Keeps your system lean and predictable 5. Recommendations
• Get recommendations for commonly safe thumbnail sizes
• Highlights WordPress core and WooCommerce-related sizes
• Helps identify likely unused custom sizes
• Quickly apply suggested sizes before regenerating or pruning 6. Scoped Processing
• Limit operations to specific folders (year/month)
• Safer testing on large Media Libraries

❌ What it does NOT do

• It does NOT delete original full-size images
• It does NOT modify image quality or compression
• It does NOT replace image optimization plugins
• It does not automatically run actions without your confirmation

🎯 Who is it for?

• WooCommerce stores with heavy image usage
• Sites using multiple themes/page builders
• Developers cleaning legacy media bloat
• Anyone hitting disk limits or slow backups

Features

• 4-tab UI: Regenerate, Recommendations, Prune Files, Thumbnail Sizes
• Batch processing with AJAX (no timeouts)
• Dry-run preview before deletion
• Smart orphan detection
• Progress bars + live feedback
• Future upload size control
• Multisite compatible (run per site)
• Recommendation engine for safer cleanup decisions
• WooCommerce-aware protected size detection
• Apply recommended sizes with one click

Installation

1. Upload the plugin to /wp-content/plugins/ or install via WordPress.
2. Activate the plugin.
3. Go to Tools → Thumbnail Manager.

Usage Recommended Workflow

1. Go to Recommendations
2. Scan media usage suggestions
3. Apply recommended sizes
4. Go to Thumbnail Sizes
5. Save changes and run regenerate
6. Review and clean old thumbnails in Prune Files

Prune Files

1. Select sizes to KEEP
2. Run Dry-run first
3. Review results
4. Switch to Delete and execute

Thumbnail Sizes

• Enable/disable sizes for future uploads
• Does NOT affect existing images until prune/regenerate is used

Frequently Asked Questions Will this delete my original images? No. Only generated thumbnails are affected. Should I back up first? Yes. Always back up before deleting files. What is “Orphan discovery”? It detects thumbnails on disk that are no longer registered in WordPress. When should I use Regenerate? After changing enabled sizes — to rebuild correct thumbnails. Are Recommendations fully automatic? No. Recommendations are based on protected/core thumbnail sizes and common usage patterns. Always review suggestions and use Dry-run before deleting thumbnails. Does it unregister sizes? No. It prevents generation using filters instead. Is it safe for large sites? Yes. Uses batch processing and folder scoping. Screenshots

1. Regenerate tab with progress system
2. Recommendations tab with suggested sizes
3. Prune Files with dry-run preview
4. Thumbnail Sizes configuration panel

Technical Notes

• Uses intermediate_image_sizes_advanced to control generation
• Uses AJAX batching to avoid server timeout
• Safe file targeting via pattern matching
• Requires manage_options capability

Changelog 1.2 (May 9, 2026)

• ✨ Added Recommendations tab for safer thumbnail cleanup decisions
• ✨ Added recommendation engine for WordPress core and WooCommerce-related sizes
• ✨ Added one-click “Apply recommended sizes”
• ✨ Added improved workflow: Recommendations → Sizes → Regenerate → Prune
• ✨ Added scoped regenerate processing:
• All media
• Current year
• Specific uploads folders
• Specific attachment IDs
• ✨ Added “Force regenerate all” option
• ✨ Added “Only generate missing thumbnails” optimization
• ✨ Added “Save changes and run regenerate” workflow
• ✨ Added Regenerate as the default tab
• 🔧 Improved regenerate batching and UI progress handling
• 🔧 Improved AJAX architecture and tab interaction handling
• 🔧 Improved overall media optimization workflow for large sites

1.1 (Mar 19, 2026)

• ✨ Added Regenerate Thumbnails feature with batch processing and progress UI
• ✨ Added “Save changes and run regenerate” workflow
• ✨ Set Regenerate tab as default entry
• ✨ Improved UX flow between Sizes → Regenerate → Prune
• ✨ Added automatic trigger for regenerate after saving sizes
• ✨ Improved admin JS handling for multi-tab interaction
• 🔧 Refactored internal handlers for regeneration logic
• 🔧 Improved performance for large media libraries

1.0.1 (Dec 3, 2025)

• Added full translation support
• Improved UI labels and formatting
• Accessibility improvements

1.0 (Oct 5, 2025)

• Initial release
• Prune Files with dry-run and batch deletion
• Orphan detection
• Disable sizes for future uploads

Upgrade Notice 1.2 Major update introducing Recommendations and advanced Regenerate workflow. Recommended workflow: Recommendations → Thumbnail Sizes → Regenerate → Prune. Privacy This plugin does not collect or transmit any personal data.\ All operations are performed locally on your server.