How to change all the images in post content to full/orginal size – Thumbnails are broken
If you have access to WP CLI, make a backup of your database (I like using WP-CLI db export), and then use the search-replace command to change image URLs (untested): wp search-replace “-150×150.jpg” “.jpg” –include-columns=post_content Remember to change and run the command for every image size and file extension.