Optimole vs pngcrush

Optimole is a web service for optimizing and delivering images across WordPress sites and other integrations. It resizes images for a visitor’s device and screen, adjusts quality based on device and connection, and supports conversion or delivery in WebP and AVIF. Its WordPress plugin optimizes uploaded images in real time, while sites beyond WordPress can connect through custom integration. The Media API provides more than 50 URL-based image transformations, and API access is available. Digital Asset Management includes a central media library, folders, tagging, and filtering; teams can use access controls and share assets with external stakeholders. Optimole uses Amazon CloudFront, which it says has more than 450 locations worldwide. Its Free plan costs nothing and allows 2,000 monthly visits, unlimited images, and unlimited sites. A free trial is promoted without a credit card requirement, and purchases have a 7-day no-questions-asked money-back guarantee. Monthly and yearly billing are offered, with yearly billing marked to save 20%.

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.