Regenerate Thumbnails
Our take
Regenerate Thumbnails does one job well: after a theme switch or new image sizes, it recreates thumbnails so images stop looking stretched or blurry. Updates are rare and it has not been marked as tested with the newest WordPress, so if you have WP-CLI access, its media regenerate command does the same job faster.
Good
- Simple and focused
- Regenerates one image or the whole library
- Can delete thumbnail sizes you no longer use
Watch out
- Rarely updated, not tested with the latest WordPress
- Slow on very large media libraries
When you upload an image, WordPress creates several smaller copies in the sizes your theme asks for. Change the theme or the image settings later and the old uploads keep their old sizes, which can lead to blurry, stretched or oddly cropped pictures. Regenerate Thumbnails recreates those copies in the current sizes.
How to use it
Go to Tools, Regenerate Thumbnails to rebuild every image, or start it for a single image from the media library. You can choose to skip sizes that already exist and to remove old sizes your theme no longer uses, which frees disk space.
Good to know
- Maintained by Automattic and the community since the original author passed away in 2019
- Sends no data anywhere and adds nothing to the front end
- For very large libraries, WP-CLI is the faster option
Install from your dashboard
In WordPress, go to Plugins, then Add New. Search for “Regenerate Thumbnails” and click Install, then Activate.
Install from the zip file
Download the zip on this page. In WordPress, go to Plugins, then Add New, then Upload Plugin. Choose the file, click Install Now, then Activate.
Requires WordPress 4.7 and PHP 5.2.4 or newer.
When do I need to regenerate thumbnails?
After switching to a theme with different image sizes, adding a new size, or changing the sizes under Settings, Media. Old uploads keep the previous sizes until you regenerate them.
Is there an alternative without a plugin?
Yes. If you have command line access, run wp media regenerate with WP-CLI.