please define secure in online.
maybe: https://wallet.mynxt.info/
I can provide information about the security of the wallet if necessary.
Okay, please provide.
In short:
1) Nxt Account Private Keys are 50 chars randomly generated by cryptographic standard algorithm
2) Keys are AES 256 encrypted twice. One time using a site-wide private AES key and one time using the user's salted password.
3) Only SSL is allowed through the site
If an attacker ever gets on hold of my database, they won't be able to decrypt the account private keys without having both the user password AND the site-wide AES private key.
No system is 100% safe, we all know this. But I think this wallet is much safer than simply using brain wallets (as it is today). Humans are not very good in creating and then storing truly random passwords.
Sounds pretty good. The only issue is trust involving you.