I am going to offer site visitors a compressed file ( for gallery images ). What is the compression format that is supported by ALL operating systems?
Visitors might have any operating system like windows, mac, linux etc. I want all visitors ( do not have technical knowledge ) to download compressed file and see images without installing any additional compression tool.
Hope I explained what I need.
Thanks
No compression format is supported by literally all operating systems. Some OSes don't even have a disk I/O or network I/O.
Having said that, use .zip as that's natively supported by Windows, it's the most popular format, and it's the core of several other file formats including Open Document Format and Java Archive (jar). All operating systems that are able to run Java are technically able to unpack zip files. I also assume that almost all modern operating systems have the support to unpack .zip files built in.
If you want to support ancient Unix machines as well, offer .tar.gz beside .zip. Even then, said ancient Unix machines should be able to unpack .zip as well.