MetaMask Extension — Practical Guide

What is MetaMask (quick overview)

MetaMask is a browser extension wallet that lets you manage Ethereum and compatible blockchain accounts, sign transactions, and connect to decentralized applications (dApps) directly from your browser. It acts as a bridge between your web browser and blockchain networks by securely holding private keys and exposing a controlled interface to websites that request wallet access.

Before you start — what to prepare

Have a modern browser (Chrome, Firefox, Edge or Brave). Make sure your operating system and browser are updated. Prepare a secure place to store the wallet’s secret recovery phrase (paper, offline encrypted file, or a hardware wallet backup). Never store the recovery phrase in plain text on an internet-connected device.

Installing the extension

1. Open your browser store (Chrome Web Store, Firefox Add-ons, Edge Add-ons, or Brave’s extension store).
2. Search for MetaMask and confirm the verified publisher (look for the official MetaMask fox and the developer "MetaMask" or "Consensys").
3. Click Install / Add to Browser, then pin the extension to the toolbar for quick access.

Creating a new wallet (step-by-step)

After installing, open MetaMask and follow the prompts:

1. Choose Create a new wallet (or Import wallet if you already have a recovery phrase).
2. Set a strong local password — this protects the extension on your device but doesn’t replace your recovery phrase.
3. Write down the 12-word (or sometimes 24-word) secret recovery phrase on paper and store it offline. MetaMask will show it to you once — if lost, you lose access to the wallet.
4. Confirm the phrase when prompted to finish setup.

Basic usage — accounts, sending, and receiving

MetaMask creates an account (address) visible in the extension. To receive funds, copy your address (click the account name) and share it with the sender. To send funds:

1. Click Send, paste the recipient address, enter the amount, and choose the asset (e.g., ETH, an ERC-20 token).
2. Adjust the gas fee if needed; higher fee = faster confirmation.
3. Review the transaction details in the MetaMask popup and confirm.

Connecting to dApps

When you visit a dApp (e.g., a DeFi platform or NFT marketplace), it may request access to your wallet. MetaMask will open a popup showing the request.

• Always verify the site’s domain before approving.
• Approve only account access that you trust; you can disconnect later from MetaMask’s Connected sites settings.

Networks — switching & adding custom networks

MetaMask supports multiple networks: Ethereum Mainnet, testnets (like Goerli), and other EVM-compatible networks (Polygon, BSC, Avalanche). Use the network selector at the top of the extension to switch networks.

To add a custom network manually, click Settings → Networks → Add Network and provide:

• Network name
• RPC URL
• Chain ID
• Currency symbol (optional)
• Block explorer URL (optional)

Managing tokens

Tokens do not automatically show in MetaMask. To display a token, click Import tokens and paste the token contract address. Double-check contract addresses from official sources before adding.

Security best practices

Advanced features

MetaMask includes several features power users appreciate:

• Swap: Built-in token swap aggregates liquidity sources; compare rates before confirming.
• Hardware wallet support: Connect Ledger/Trezor to create a secure signing flow.
• Custom RPCs: Add developer networks or public RPC endpoints for different chains.
• Multiple accounts: Create or import multiple addresses and label them for organization.
• Advanced gas controls: Set EIP-1559 parameters (max fee, priority fee) when available.

Common problems & quick fixes

1. Extension not opening: Restart browser, ensure it's enabled in extension list, or reinstall from official store.
2. Balance mismatch: Ensure you are on the correct network; token balances depend on network and token contract visibility.
3. Pending transactions: If a transaction is stuck, you can speed it up by replacing it with a higher fee or cancel by sending a zero-value transaction with the same nonce and higher gas (advanced).
4. Lost access: Restore with the recovery phrase using Import wallet on any fresh MetaMask install or compatible wallet.

Privacy considerations

MetaMask exposes your public addresses to any site you connect to. Use separate accounts for different activities to reduce traceability, and consider using privacy-preserving tools and networks if needed. Be mindful that blockchains are public ledgers — transactions are visible unless you use privacy technologies (e.g., mixers, privacy chains) which come with their own risks and legal considerations.

Practical tips

• Create a small “hot” wallet for daily interactions and keep larger funds in a hardware wallet or cold storage.
• Double-check URLs for phishing sites. Bookmark dApps you trust instead of clicking random links.
• When testing, use testnets and faucet tokens before working with mainnet funds.
• Use the Connected sites section to revoke dApp connections you no longer use.

When to use MetaMask vs a hardware wallet

MetaMask is excellent for convenience and everyday dApp use. For significant holdings or high-value transactions, pair MetaMask with a hardware wallet or manage keys in hardware directly. A hardware wallet keeps private keys off your computer and requires physical confirmation for transactions — a strong guard against remote compromise.

Final checklist

1. Installed official MetaMask extension from browser store.
2. Created a wallet or imported one with recovery phrase safely stored offline.
3. Connected only to trusted dApps and reviewed transaction details before approving.
4. Considered hardware wallet for significant assets and periodically reviewed token approvals.