MetaMask Wallet — Secure Non-Custodial Web3 Wallet

What is MetaMask Wallet?

MetaMask is a software wallet that lets you manage crypto assets, interact with smart contracts, and connect to decentralized applications directly from your browser or smartphone. It stores private keys locally (encrypted), never transmits them to websites, and asks for user approval whenever a transaction must be signed. Because it is non-custodial, you retain full control of your funds—but you also carry sole responsibility for backing up and protecting your recovery phrase.

Key features

Install & Setup — Safe steps

Install only from the official site: visit metamask.io and follow the download links for your browser or mobile store. The official page directs you to the right extension store entry or app store listing.

1. Add the extension or install the mobile app from the official sources.
2. Create a new wallet or import an existing one using your Secret Recovery Phrase (seed)—do this only inside the extension/app UI.
3. Write your Secret Recovery Phrase on paper or use a metal backup plate; never store it in cloud storage or as a screenshot.
4. Choose a strong password for local unlocking and enable native device protections (biometrics on mobile, OS lock).

How to use MetaMask (user perspective)

Most dApps provide a “Connect Wallet” button. When clicked, the dApp will request account access from the wallet. MetaMask then prompts you to approve the connection and choose which account to expose. After connecting, the dApp may request additional operations such as message signing or transaction approvals — MetaMask always shows the details (method, value, gas) for your review before signing.

Best practice: use separate accounts for different dApps to reduce linkability and risk exposure. Confirm receiving addresses on-device or via trusted UI checks when copying addresses between systems.

Developer integration — minimal examples

Developers interact with MetaMask through the injected provider `window.ethereum`. Below are concise, secure examples for common tasks.

// Request account access (connect)
if (window.ethereum) {
  try {
    const accounts = await window.ethereum.request({ method: 'eth_requestAccounts' });
    console.log('Connected address:', accounts[0]);
  } catch (err) {
    console.error('User rejected connection or an error occurred', err);
  }
} else {
  alert('MetaMask is not installed. Visit https://metamask.io');
}

// Listen for changes
window.ethereum.on('accountsChanged', (accounts) => { /* update UI */ });
window.ethereum.on('chainChanged', (chainId) => { /* handle network change */ });

Important: never request or ask users to provide private keys or seed phrases. Use the provider to request signatures and present clear UX that explains what each transaction does.

Privacy & network considerations

Using MetaMask exposes your wallet address to any connected dApp, which can create linkability across services. To reduce privacy risk, use dedicated accounts per dApp and consider privacy tools where appropriate. Switching RPC endpoints can change which node sees metadata; choose reputable providers when adding custom RPCs.

Troubleshooting & common issues