Some games (like those with lots of video) won't shrink much.

In the world of emulation, especially for handheld devices like the PlayStation Portable (PSP), storage space is a precious commodity. While modern SD cards offer hundreds of gigabytes, retro game collections (PS1, PS2, and PSP ISOs) can quickly eat up every last megabyte. Enter the —a niche but powerful tool that promises better compression than standard ZIP or CSO, without the performance penalties.

While they exist, uploading a 4 GB game to a random website is a privacy and legal gray zone. Stick to local tools.