Once you hit the "Send" button, Cryptonator puts your transaction in the sending queue. Time required to send your transaction out to the network depends on its place in the sending queue, and normally takes less then a minute.
However, settlement of outgoing transactions is governed by the speed of confirmations on the blockchain (the public ledger of all cryptocurrency transactions). Typically, a single confirmation on the Bitcoin blockchain happens within ten to twenty minutes, Litecoin and Dogecoin - within two to five minutes.
Confirmation time varies from currency to currency and does not depend on Cryptonator, but on the speed of the particular cryptocurrency protocol. In some cases, it may take up to several hours. Especially when a network is overloaded with transactions.
You can easily check whether the bitcoin network is overloaded by checking number of unconfirmed transactions here.