It is the standard for speeding up websites. Servers "gzip" text-based files (HTML, CSS, JS) before sending them to browsers, which can reduce file sizes by up to 70-80% . "Solid" Compression vs. Standard Gzip
If you need to compress a directory into a solid Gzip archive on or macOS : 12353sckgzip
If you are looking for "solid content" regarding Gzip and compression, What is Gzip Compression? It is the standard for speeding up websites