pngcrush vs TinyPNG

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.

TinyPNG is an image compression service offering lossy compression, batch processing, resizing, metadata controls and API access. It supports JPEG XL, AVIF, WebP, JPG, PNG and APNG files. Free web use allows up to 20 image compressions per session, with each image limited to 5 MB, and up to three conversions per session. The API includes 500 free compressions each month; unused free compressions reset at the start of each calendar month and do not roll over. Above that allowance, charges apply to successful compressions, with no subscription fee or minimum charge. Uploaded images are accessible only to the uploader and retained for a maximum of 48 hours. TinyPNG removes unnecessary metadata, while the API can preserve selected copyright, location and creation-date metadata. Official plugins are available for WordPress and Figma, alongside a beta Zapier integration. Web Pro offers unlimited compressions and a 75 MB per-image limit, while Web Ultra allows 150 MB images and unlimited conversions. The maker is headquartered in Hoevelaken, Netherlands.