MetaMask is a software cryptocurrency wallet used for interacting with the Ethereum blockchain. It enables users to access their Ethereum wallet through a browser extension or mobile application, allowing them to interact with decentralized applications. Developed by ConsenSys, a blockchain software company focused on Ethereum-based tools and infrastructure.

MetaMasks Overview

MetaMask allows users to securely store and manage their account keys, broadcast transactions, and send/receive Ethereum-based cryptocurrencies and tokens. It provides a secure connection to decentralized applications through compatible web browsers or the built-in browser of its mobile application.

Websites or other decentralized applications can connect, authenticate, and integrate with users' MetaMask wallets (as well as other similar blockchain wallet browser extensions) using JavaScript code. This allows websites to send action prompts, signature requests, or transaction requests to users through MetaMask as an intermediary.

The application includes a comprehensive service called MetaMask Swaps, which aggregates multiple decentralized exchanges (DEXs) to find the best rates for exchanging Ethereum tokens. A service fee of 0.875% of the transaction amount is charged for this feature.

According to Bloomberg, as of November 2021, MetaMask's browser extension has over 21 million monthly active users.