The MetaMask app is both a wallet & a browser. Buy, send, spend & exchange your digital assets. Make payments to anyone, anywhere.Metamask is a sort of Ethereum wallet that fills the gap between the user's interface for Ethereum with the regular web.The wallet is online, so it's more at risk than hardware wallets or offline “cold” wallets. Like any “hot” wallet, assets stored on Metamask can be compromised via security vulnerabilities on your device or internet connection.