Many games include large blocks of zeros (0x00) or repeating patterns. These compress to near-nothing using delta encoding or simple run-length encoding. A tool like PS2 Dummy Remover or UltraISO can strip these sectors, producing a —often 60–80% of the original size.
: Widely considered the best modern format for PS2. It offers lossless compression, meaning no game data is lost, and it is natively supported by emulators like CSO (Compressed ISO) ps2 iso files highly compressed full
If you are searching for pre-compressed full games online (e.g., a "500MB download for a 4GB game"), you will likely encounter one of two things: 1. Rip Kits (Stripped Content) Many games include large blocks of zeros (0x00)
The Ultimate Guide to PS2 ISO Files: Highly Compressed & Full Versions meaning no game data is lost