I don't know, I've never used 7-zip except maybe once when I might have had to open a filetype WinRAR doesn't support. I use WinRAR, but it's just out of habit. It's what I've always used. It would probably be better if I used 7-zip just because WinRAR has a pop-up window I have to shut first every time I use it since I haven't paid for it.