Anyone know the best way to get a free CARFAX report?

I'm checking out a few used cars this week and I'm trying not to spend a fortune pulling history reports on every single one.

I searched for "free CARFAX" and found a bunch of websites claiming they offer free reports, but most of them either look sketchy, ask you to sign up for something, or don't actually give you the report.

Is there any legit way to get a free CARFAX report, especially for private seller cars? Or do most people just end up paying every time they want to check a VIN?

Just curious what everyone here does before buying a used car. I'd rather avoid wasting money if there's a better option.