The EWWW Image Optimizer plugin keeps track of every image that it processes in a custom table. It does this, so that the optimizer can avoid re-optimizing the same image UNLESS the file-size has changed. If you regenerate thumbnails, or edit an image, apply watermarks, or anything of that nature, the file size will likely change, and EWWW IO will re-optimize the image automatically.
However, sometimes you need to force the plugin to re-optimize an image, or maybe even your whole library. In the Media Library (list mode) there is a Re-optimize option that will force the plugin to ignore the fact that an image was already processed. Additionally, there is a check-box on the Bulk Optimizer that allows you to force the plugin to re-optimize all your images.
But wait, what will that actually do?
- If you are using Pixel Perfect (lossless) mode, this should do nothing the second time around, except sometimes for PNG images, since the parameters are somewhat randomized in optipng.
- If you have switched from Pixel Perfect to a higher level, this will allow you to gain additional savings from using our compression API.
- If you were already using a Premium mode, and re-optimized on the same or higher level, you may get more savings, and even a savings of 100 bytes will use up image credits, so use this with caution.