In one aspect, support for hash based xcopy replication for synchronous replication is provided. An aspect includes determining, in response to an xcopy command, whether a source logical unit (LU) and a target LU are in active synchronous replication to the same target site. Upon determining that the LUs are in active synchronous replication, increasing a count of a hash handle list, obtaining a unique full hash digest, and sending the digest with volume replication pairing identifier, offset, and length to the target. Upon receiving a request from the source, searching, by the target, for local hash handles of the digest; and upon determining the local hash handles exist in the digest, incrementing, the reference counter handle list, and sending corresponding hash handles from the source site to the target.