Regenerating media thumbnails with WP-CLI

When you change your WordPress theme, the new theme may require different image sizes to what the old theme used. Images uploaded before the theme switch will not automatically generate the new sizes, which can cause thumbnails to look wrong or appear missing. The wp media regenerate command rebuilds all thumbnail sizes for your existing images.

When to use this command

• After switching to a new theme
• After installing a plugin that adds new image sizes
• If images on your site look stretched, cropped incorrectly, or are showing as broken thumbnails

Command reference

Command	What it does
wp media regenerate	Asks for confirmation then regenerates all thumbnail sizes for all images
wp media regenerate --yes	Regenerates all thumbnails without asking for confirmation
wp media regenerate <id>	Regenerates thumbnails for a specific image by its attachment ID
wp media regenerate --only-missing	Only generates thumbnail sizes that are missing, skipping existing ones (faster)

Warning about large media libraries

This command can take a long time on sites with many images. The terminal session must stay open during the process. For very large libraries, it may time out. Contact support if this happens.

Need help?

If you have questions about regenerating media, visit our support page or email hello@smarthost.ie.