Description
Product page | Documentation | Support
Thumbnail Manager helps regenerate WordPress image sizes, prevent future thumbnail bloat, and review generated files before cleanup. Use it after changing themes or WooCommerce image settings, migrating a site, or finding obsolete sizes in a long-running Media Library.
Large operations run as persistent, cursor-based jobs. They continue in bounded batches, survive a page reload or network interruption, and can be limited to selected upload years or months.
Thumbnail control and regeneration
- Review every registered image size and decide which sizes WordPress should generate for future uploads.
- Generate only missing sizes or force-regenerate selected image attachments.
- Process all images, selected attachments, the current year, or selected upload folders.
- Review recommendations based on protected WordPress sizes, WooCommerce-related sizes, attachment metadata, and common content references.
- Resume or cancel persistent jobs and review recent job results and per-item errors.
Review-first cleanup
Prune Files separates discovery from deletion:
- Choose the image sizes to keep.
- Scan all uploads or selected year and month folders.
- Review the immutable, hashed manifest and estimated storage total.
- Explicitly approve the reviewed manifest.
- Delete only those approved generated files in resumable batches.
Original full-size uploads are protected. Candidate paths are validated inside the WordPress uploads directory, and attachment metadata is updated when a generated size is removed.
Metadata-backed legacy sizes can be included in the review. Disk-only files that match a -WIDTHxHEIGHT pattern but cannot be mapped reliably to attachment metadata are reported and skipped by default.
Scope
Thumbnail Manager controls image-size generation, regeneration, and cleanup. It does not compress images, convert them to WebP or AVIF, configure a CDN, offload media, or unregister a size from the theme or plugin that originally registered it.
Recommendations are an informed starting point. Verify the sizes used by the active theme, plugins, WooCommerce templates, and custom code before disabling generation or approving deletion.
Privacy
Thumbnail Manager does not collect, store, or transmit personal data to external services. Thumbnail analysis, regeneration, recommendations, and cleanup run locally on the WordPress site.
Screenshots
Installation
- Install the plugin through the WordPress Plugins screen, or upload it to
/wp-content/plugins/thumbnail-manager/. - Activate Thumbnail Manager.
- Go to Tools > Thumbnail Manager.
- Run Recommendations and review the result for your theme and plugins.
- Configure future Thumbnail Sizes before regenerating or cleaning files.
- Back up the uploads directory before approving cleanup on a production site.
FAQ
-
Can I regenerate thumbnails after changing image sizes?
-
Yes. Only Missing creates absent sub-sizes. Force Regenerate rebuilds the selected attachments more comprehensively from an available original image source.
-
Can it clean unused generated thumbnails?
-
Yes. Prune Files first builds a manifest for review. Nothing is deleted until the scan finishes and an administrator explicitly approves that manifest.
-
Will it delete original images?
-
No. Original full-size uploads are protected. Cleanup candidates must also pass path and attachment checks.
-
Can I scan several upload folders?
-
Yes. Search for and select multiple years or months. Selecting an entire year automatically covers its month folders.
-
Is it suitable for a large Media Library?
-
Yes. Recommendations, regeneration, scanning, manifest creation, and deletion use persistent jobs and bounded batches that can resume after interruption.
-
What happens if I close the page during a job?
-
The job state remains in the database. Reload the admin page to resume it. Cancelling stops future batches while retaining an audit record.
-
Does orphan discovery delete disk-only files?
-
No. Unmapped disk-only filename matches are reported and skipped by default. Only approved, validated manifest items are deleted.
-
Is it safe for WooCommerce sites?
-
The plugin recognizes WooCommerce-related sizes in Recommendations, but storefront requirements vary. Verify the sizes used by your store before disabling or pruning them.
-
Does disabling a size unregister it from a theme or plugin?
-
No. It changes which registered sizes WordPress generates for future uploads. The original registration remains in place.
Reviews
Contributors & Developers
“Thumbnail Manager” is open source software. The following people have contributed to this plugin.
Contributors
Translate “Thumbnail Manager” into your language.
Interested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.4.0 (Jul 17, 2026)
- Added persistent jobs with ownership, expiry, cancellation, locking, resume, and per-item errors.
- Split cleanup into scanning, immutable manifest review, explicit approval, and resumable deletion.
- Added searchable multi-folder selection and limited scans to selected upload folders.
- Improved force regeneration, batched Recommendations, admin responsiveness, and automated release coverage.
See changelog.txt for the complete release history.