Real Thumbnail Generator – Efficiently Regenerate Thumbnails in Mass (Lite)


Turn your WordPress media thumbnails to the next level with fast mass regeneration. Single or bulk regenerate images and create a custom thumbnail upload structure with this unique plugin (Pro).

RTG (Real Thumbnail Generator) Lite allows you easily to regenerate all your (existing) thumbnails in your media library. You can regenerate a single or bulk images. The regeneration of thumbnails can up to be 33 % faster than other plugins due to chunked regeneration. Just install this plugin and it works fine with all your image and media files. It also supports multisite.

Features (Lite):

  • WordPress 5.0 ready
  • Single regenerate images in media library table, grid and attachment view mode
  • Bulk regenerate in media library (table and grid mode)
  • Works great with PDF files (WP 4.7+ required)
  • Regenerate your whole media library
  • Works with your existing images
  • Can be up to 33 % faster than other plugins because RTG uses less requests to regenerate
  • GPDR / DSGVO: The plugin is collecting no personal data!
  • Compatible with touch devices
  • Supports multisite

PRO Version available with additional features:

  • Skip already existing thumbnail files
  • Only regenerate a set of image sizes, that means if you have registered a new image size you can only regenerate that one. That means you can skip other image sizes.
  • Custom upload structure for thumbnail pathes and filenames (you can define a pattern with placeholders)
  • Detect unused image sizes (for example after theme switch) and delete them
  • One time payment, forever free updates
  • Fast support

→ Interested in the Pro version?


  • A new "Thumbnails" button is added to the media library
  • You can analyse all your items to recalculate the index
  • Or directly bulk rengerate your images
  • Jump from single file to single view
  • Single view
  • Available settings


  1. Goto your wordpress backend
  2. Navigate to Plugins > Add new
  3. Search for « WP Real Thumbnail Generator »
  4. « Install »


  1. Download the plugin from this site (
  2. Copy the extracted folder into your wp-content/plugins folder
  3. Activate the « WP Real Thumbnail Generator » plugin via the plugins admin page


What does « Custom upload structure » mean?

The custom upload structure can be easily set in the media settings of the Pro version. Here is a little example how the WP standard upload looks like:
… and after you set a custom upload structure it can look like:


9 setembre 2019
This review is for the Premium version! The task was to migrate a Joomla! page to WordPress and the customers were not happy with WordPress´ media file management. They used to create a physical folder per blog post, add the images for this post and create a slider out of all images in this folder. WordPress had to be tricked into that sort of media management with the help of @mguenter´s plugins "Real Media Library" (free) "Physical Custom Upload Folder" (premium) and Real Thumbnail Generator" (premium). What is special about this plugin? There are a few plugins out there that allow generation of a physical upload folder within /wp-content/uploads. The thing is: WordPress automatically generates thumbnails for every image within the folders and adds them to the folder. So, the sliders contain not only the images themselves, but the thumbnails as a "bonus". This plugin allowed me to generate the thumbnails in a sub-folder, so they are not added to the sliders. Yay! Works perfectly well, saved me some coding time and is, as far as I found, the only plugin to do so.
Read all 1 review

Contributors & Developers

“Real Thumbnail Generator – Efficiently Regenerate Thumbnails in Mass (Lite)” is open source software. The following people have contributed to this plugin.



07 October 2019 – Version 2.0.5

  • Fixed bug with thumbnails path when using %size-identifier%
  • Fixed bug with 503er server errors and retry regenerate again

21 August 2019 – Version 2.0.4

  • Added search by filename in Analyse / Regenerate tab
  • Fixed bug with WooCommerce thumbnails and custom cropping
  • Improved error handling so the process does not stop when an error occurs
  • Improved performance by only loading images when hovering in analyse item
  • Improved performance by list virtualization
  • Improved height of opened analyse dialog

09 August 2019 – Version 2.0.3

  • Fixed bug with page reload in « Edit attachment » page
  • Fixed bug while error is logged when opening an attachment in the dialog
  • Fixed bug when attachment is deleted and shows still as « Unused »
  • Improved regeneration list that now all items are clickable
  • Released lite version

19 March 2019 – Version 2.0.2

  • Fixed bug with style/script dependencies

21 February 2019 – Version 2.0.1

  • The plugin is now fully compatible with Crop-Thumbnails plugin
  • Fixed bug with Internet Explorer
  • Fixed bug with icons
  • Fixed bug with PDFs

15 February 2019 – Version 2.0

  • Complete code rewrite
  • … Same functionality with improved performance
  • … with an eye on smooth user interface and experience
  • Added option to skip existing thumbnail files
  • Added autoupdater functionality in Plugins > « License settings »
  • Added checbox to select / deselect all registered thumbnail sizes
  • Fixed bug with generation of single thumbnail sizes
  • Fixed compatibility with Simple Matted Thumbnails
  • Fixed compatibility with EWWW Image Optimizer
  • Improved performance and usability

23 March 2018 – Version 1.1.7

  • Added « Regenerate » button to PDF files in list view
  • Fixed bug with PDF thumbnails while getting « -1 » prefix

22 March 2018 – Version 1.1.6

  • Fixed bug with PDF generation in thumbnail folders
  • Fixed bug with deletion of old thumbnails when changing the thumbnails schema
  • Fixed bug with deletion of empty thumbnail folders

10 October 2017 – Version 1.1.5

  • Fixed bug with duplicate info containers about thumbnails

25 May 2017 – Version 1.1.4

  • Added option to set a chunk size for regeneration

14 April 2017 – Version 1.1.3

  • Fixed bug with SVG images

03 February 2017 Version 1.1.2

  • Fixed bug with AJAX Search Pro
  • Fixed bug with Facebook hint in plugins site

04 January 2017 – Version 1.1.1

  • Fixed bug with failed thumbnail sizes
  • Fixed bug with .txt upload
  • Fixed bug with regenerating only a set of sizes

09 December 2016 – Version 1.1

  • Added ability to regenerate only specific image sizes
  • Fixed bug with copped image sizes

29 November 2016 – Version 1.0.1

  • Added the MatthiasWeb promotion dialog

10 November 2016 – Version 1.0

  • initial review