Introduction MetaMask is a non‑custodial cryptocurrency wallet and gateway to Web3, developed by ConsenSys and first released in 2016. It started as a browser extension, allowing users to interact with Ethereum and other EVM‑compatible blockchains directly from their browser. Over time, MetaMask expanded to include a mobile app for iOS and Android, offering on‑the‑go access to decentralized applications (dApps), decentralized finance (DeFi) platforms, and NFT marketplaces. By storing users’ private keys locally and enabling seamless smart contract interactions, MetaMask has become one of the most widely used crypto wallets in the world.

Installation & Setup MetaMask is available as a free extension for Chrome, Firefox, Brave, and Edge, and as a standalone mobile app. To set up MetaMask:

1. Browser Extension
   • Visit metamask.io, click “Download,” and select your browser.
   • Add the extension from the official extension store.
   • Choose “Create a Wallet” or “Import Wallet,” set a strong password, and securely record your 12‑word Secret Recovery Phrase.
2. Mobile App
   • Download from the App Store or Google Play (“MetaMask – Blockchain Wallet”).
   • Tap “Get Started,” then create or import using your recovery phrase.
   • Optionally enable biometric unlock for added convenience.

Core Features

• Account Management: Create and manage multiple Ethereum accounts. Switch networks or import additional accounts at any time.
• Custom Networks: Connect to any Ethereum Virtual Machine (EVM) chain—such as Polygon, Binance Smart Chain, Avalanche, or Arbitrum—by entering RPC details.
• Token & NFT Support: View ERC‑20 tokens and ERC‑721/ERC‑1155 NFTs. Add custom tokens via contract address.
• Swaps: Built‑in aggregator sources liquidity from major decentralized exchanges, enabling users to trade tokens directly within the wallet with competitive rates.
• Transaction Signing: All transaction and message signing occurs locally. MetaMask prompts for user confirmation before broadcasting any signature to the network.

Security & Privacy MetaMask is non‑custodial: users retain full control over their private keys, which are encrypted in the browser or mobile secure storage and never leave the device. Key security practices include:

• Secret Recovery Phrase: The only backup method. Users must store it offline—anyone with access to the phrase can control the wallet.
• Local Encryption: Wallet data is encrypted with a user‑chosen password. Closing or locking MetaMask requires re‑authentication.
• Phishing Protection: MetaMask warns users when visiting known malicious sites; however, users must remain vigilant and always verify URLs.
• Open‑Source Audits: MetaMask’s code is publicly available on GitHub, subject to community and formal security audits.

Integrations & Use Cases MetaMask’s in‑page API (window.ethereum) is detected by thousands of dApps, enabling seamless “Connect Wallet” flows for DeFi protocols (Uniswap, Aave), NFT platforms (OpenSea, Rarible), and on‑chain games. WalletConnect compatibility further extends MetaMask’s reach, allowing mobile users to link to desktop dApps. Power users can leverage MetaMask’s developer APIs and internal JSON‑RPC proxy to build custom integrations, bots, or dashboards.

Mobile vs. Desktop

• Desktop Extension: Ideal for heavy dApp interaction, detailed portfolio management, and quick network switching.
• Mobile App: Combines portability with core features—portfolio overview, transaction history, QR‑code scanning, and push notifications for incoming transactions.

Conclusion MetaMask stands at the forefront of the decentralized web, bridging users and blockchain services with security and ease of use. Its non‑custodial design, broad network support, and extensive dApp integrations make it both a gateway for newcomers and a powerful tool for seasoned Web3 enthusiasts. Whether you’re swapping tokens, staking assets, minting NFTs, or exploring new blockchains, MetaMask provides the foundational access point for your on‑chain journey.