It can use both BIPs since you guys gave two different answers? I assume It can't... so how exactly to know? simply typing it in the given website is enough? or It will give results whether the seed is correct or not?
i don't think these BIPs have anything to do with each other to use them both, although you have to check the BIP description itself to make sure.
and as for the site, yes you put in the "Seed" and it generates the master private keys and a list of addresses with their private keys at the bottom (Derived Addresses)
although as i said, check the code first. then run offline.