JPEGmini is a photo and graphics application that enables users to reduce the file size of their digital photographs while still maintaining high quality. It works by analyzing each image and then applying advanced algorithms to reduce its size up to 80 percent without affecting its visual quality. JPEGmini can be used as a desktop application, mobile app, or web application. The desktop version offers an easy-to-use interface to allow users to quickly reduce the size of their digital photographs. The mobile app allows users to optimize images on their smartphone or tablet. The web version allows users to optimize images directly from their web browser. JPEGmini also offers a range of features, including support for different image formats, the ability to optimize multiple images at once, the ability to resize images, and more.
The discontinued official jStrip site is no longer accessible, but has been archived by Archive.org: https://web.archive.org/web/20150516175309/http://davidcrowell.com/jstrip
does almost the same, but only on macOS