Web based wallet is never secure. It's a good place to keep smaller amounts of money that you can pay with, but don't use it to store all your savings.

Windows, Linux, Mac
Web
third party control
Cryptocurrency wallets, like My Monero help you store your coins so they're not exposed on the exchange.
Web based wallet is never secure. It's a good place to keep smaller amounts of money that you can pay with, but don't use it to store all your savings.