Splitting people into fair teams by hand always ends in "that's not even!" A random team generator does it instantly and impartially: paste your list of names, choose how many teams you want, and it shuffles everyone into balanced groups, no favouritism, no arguments.
Yes, TossGenie shuffles the list with your browser's cryptographic random generator (a proper Fisher-Yates shuffle), so every arrangement is equally likely and teams come out as even as the numbers allow.