PNG to JPG Conversion for existing images

That’s a good question, any links in the wp_posts table will be updated by EWWW IO when an image is converted. If a plugin is storing image URLs elsewhere, then you would need to update those manually. Most often, any stale links will be in cached data, so clearing caches or regenerating CSS from page builders takes care of most of that sort of thing.

I tested this in the meanwhile and I noticed that the image is well converted to JPG but the file’s extension remains as PNG – is that correct?

The one stored in the database should be .jpg, but unless you enable Delete Originals, it will still leave the .png version on disk. Is that what you’re seeing?

I rested with another file and I see that everything is converted to JPG and all links inside posts are updated.

And I have enabled the option “Include Originals” so now I see by FTP that all files have changed extensions.

Thanks for your feedback, that’s fine!