IP version

✓Residential — supported—Rotating ISP — not supported—Rotating DC — not supported

Restrict which IP version your exit uses.

Usage

# IPv4 only
curl -x USERNAME:[email protected]:8000 https://api.ipify.org

# IPv6 only
curl -x USERNAME:[email protected]:8000 https://api.ipify.org

Neither flag takes a value.

Send one or the other, never both

The pool cannot contain an exit that is exclusively v4 and exclusively v6, so sending both returns nothing.

Without either flag you get whatever the pool hands you, which in practice is mostly IPv4.

When IPv6 costs you requests

Plenty of targets still do not answer over IPv6 at all. If you send -v6 and requests start timing out against a site that worked before, test the target over IPv6 directly before assuming the proxy is at fault.

Combining

Both flags stack with every other option.

-country-US-region-texas-v4

Each one shrinks the pool. See How targeting works.