What is MetaMask and how does it work?

MetaMask is a crypto wallet that lets you hold tokens and connect to apps on blockchains like Ethereum. It is self-custody, which means you control the keys rather than a company. It works as a browser extension and as a phone app, and it can connect to a dapp so you can approve transactions from your own wallet.

How does the MetaMask wallet work?

When you create a wallet, MetaMask generates a 12-word Secret Recovery Phrase. Every account in the wallet is derived from it, so whoever holds those words controls the funds. You also set a password, but that only unlocks MetaMask on one device. MetaMask's support pages say it cannot recover your wallet for you, and if the phrase is lost, the funds cannot be recovered. Newer wallets can also be created with Google, Apple or Telegram login, in which case the password plays a bigger role.

MetaMask itself is free to set up, and you do not need crypto to open it. You do pay network fees, known as gas fees, when you send. Its built-in swap feature charges a 0.875% service fee as of October 2026. For background on self-custody, see custodial vs non-custodial wallets.

What is the difference between the MetaMask extension and the MetaMask app?

The extension runs in Chrome, Firefox, Brave, Edge and Opera, and suits connecting to websites on a computer. The app runs on iOS and Android. Both use the same recovery phrase, so you can import one wallet into each. Network settings do not sync between devices, though, so custom networks must be added again on each one.

How do you add a network to MetaMask?

Open the network menu and look under Additional networks. Popular networks can be added with one click. As of October 2026 the list includes Ethereum, Bitcoin, Solana, Base, Polygon, BNB Chain, Arbitrum, OP, Avalanche, Linea and others.

For a network that is not listed, choose Add a custom network and enter its details, including the RPC URL the wallet uses to talk to that chain. MetaMask warns that third-party lists of networks are not maintained by MetaMask, so check the details against the project's official documentation before saving.

If you send tokens on the wrong EVM network, MetaMask says they are usually still in your wallet. Add that network to see them.

Is MetaMask safe?

MetaMask is a hot wallet, so its safety depends heavily on how you use it. MetaMask's own guidance is to:

• Never share your Secret Recovery Phrase or private keys. MetaMask support will never ask for them.
• Only enter the phrase when creating or restoring a wallet, and confirm you are using the real MetaMask.
• Review token approvals and limit how much a dapp can spend.
• Consider pairing it with a hardware wallet for large holdings.

Common threats such as fake sites and malicious approvals are covered in crypto phishing and wallet drainers.