Image Optimizer resizes and recompresses a photo in this tab so an email or form will take it. You set scale and quality and you can compare the size. There is no promised percent, because a screenshot and a raw photo do not shrink the same way.
Keep the original. JPEG and WebP throws are lossy. A second pass on an already-small JPEG mostly adds blur. PNG screenshots often shrink more from resizing than from quality alone.
Nothing is uploaded to a FileTools Kit processing server. The download is the file you send. The source stays where you picked it.
