The images are sent to our servers for optimization, retrieved when they are ready and they replace the original version. While the folder is optimized, you need to keep this page open. A progress bar will be displayed and the optimized images will be shown in a compare pane below. For each folder, a .shortpixel file will be created, storing optimization metadata. You need to make sure that the folder has proper rights for the file creation/modification.
The optimization process for that folder will stop. But, if you reload the same page, or start the process over for that folder, the optimization process will continue where it left. The already optimized images will not be processed.
You can login to your ShortPixel account and check your usage statistics as well as a detailed optimization report. The default settings of the web optimizer are set to Lossy compression, remove EXIF, CMYK to RGB conversion, no WebP generation. You can find more about these settings on our blog.
Using a base URL instead of uploading files via POST significantly speeds up the optimization process as the files are downloaded in parallel by our servers instead of being uploaded via a multi-part POST message.
Press Ignore if this is a local site (not accessible from Internet) or if the access is restricted in any manner.