If I delete a file or image to clean up the media library, will the image used in a post disappear?
If you delete a file or image from your Media Library that has been inserted into a post or page, that image will be deleted… but it will appear as a broken link icon. So it won’t simply be removed. Instead, it will generate a missing image error.
When you’re browsing the Media Library, you’ll notice that there is a column on the right that displays whether or not the image or file has been used in a post or page. If it has been used, you’ll see a link to the post or page, which you can click to open the page/post in the Editor, then delete the image from the content and re-publish. Then, it’s safe to delete the image from your Media Library.
If an image or file has not been used in the content of a page or post, it will indicate that it is, “Unattached.”
Hope this helps!