Ashampoo ZIP Pro vs FileOptimizer

Ashampoo ZIP Pro has no write-up on Specifiction yet; its figures are above.

FileOptimizer is a free Windows program that recompresses already-compressed files to reduce their size while retaining their format and behavior. It supports batch processing and accepts files through its interface or command line; optimization replaces them with optimized versions. The maker says it handles more than 600 file extensions and identifies types by examining file contents, regardless of extension. Listed formats include APNG, AVIF, BMP, BPG, DDS, DNG, GIF, HEIC, HEIF, ICO, J2C, J2K, JP2, JPEG, JPG, JXL, MNG, MPO, PCX, PNG, PSD, SVG, TGA, TIF, TIFF, and WEBP. By default, it removes extra metadata and keeps originals in the recycle bin. The program includes more than 90 third-party tools as plugins and supports command-line automation. It is provided under the GNU Affero General Public License, free for personal and commercial use without feature limits. The maker lists Windows XP through Windows 11 and Server 2022 among its requirements. Lossy options are also documented for PNG, JPEG, and GIF.