Optimizilla vs pngcrush

Optimizilla is a web image-compression tool for JPEG, PNG, WebP, GIF, and SVG files. It processes images in the browser, supports batch work, and lets users adjust quality and preview the result before saving. The compressor uses format-specific handling: JPEG quality is inferred from quantization tables with a default target of 80; PNG files become PNG8 with up to 256 colors while preserving transparency; and animated GIF optimization reduces the palette while retaining frames. Compressed images have EXIF, GPS, and camera metadata removed. The site says files are not uploaded to its servers. Its free plan is free, with no registration, daily limit, or watermark, and is described as allowing unlimited compression. The pricing page also lists a 25 MB maximum file size and batches of up to 50 files for Free. Pro costs $9 a month and includes unlimited file size and batch uploads, among other tools. Enterprise pricing is custom and not listed; its plan includes custom integrations, without naming partners.

pngcrush is a free command-line utility for losslessly optimizing PNG files. It tries compression levels and PNG filter methods to reduce the size of a file’s IDAT datastream, and supports batch processing. Its chunk controls can remove unwanted ancillary chunks or add gAMA, tRNS, iCCP, and textual chunks. The supported format is PNG; image resizing and API access are not provided. pngcrush runs from MSDOS, UNIX, or Linux command lines, and the maker links to precompiled Windows binaries for an MSDOS window. Source code is available from SourceForge and the pmt git repository, with libpng and zlib included in the distribution. The maker permits use, modification, and redistribution without a fee; the license is equivalent to, but not identical with, the libpng license. Build choices matter: the maker warns about overflow vulnerabilities when compiling with certain older unpatched libpng versions, and says a build statically linked with the supplied zlib is believed to avoid a particular double-free bug. The SourceForge files page lists pngcrush-1.8.11.tar.xz as the latest version. Free graphical applications that embed pngcrush are also noted by the maker.