MetaMask is a

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

cryptocurrency wallet A cryptocurrency wallet is a device, physical medium, program or a service which stores the public and/or private keys for cryptocurrency transactions. In addition to this basic function of storing the keys, a cryptocurrency wallet more often al ...

used to interact with the

Ethereum Ethereum is a decentralized, open-source blockchain with smart contract functionality. Ether ( Abbreviation: ETH; sign: Ξ) is the native cryptocurrency of the platform. Among cryptocurrencies, ether is second only to bitcoin in market cap ...

blockchain A blockchain is a type of distributed ledger technology (DLT) that consists of growing lists of records, called ''blocks'', that are securely linked together using cryptography. Each block contains a cryptographic hash of the previous block, ...

. It allows users to access their Ethereum wallet through a

browser extension A browser extension is a small software module for customizing a web browser. Browsers typically allow a variety of extensions, including user interface modifications, cookie management, ad blocking, and the custom scripting and styling of web pa ...

mobile app A mobile application or app is a computer program or software application designed to run on a mobile device such as a phone, tablet, or watch. Mobile applications often stand in contrast to desktop applications which are designed to run on ...

, which can then be used to interact with decentralized applications. MetaMask is developed by ConsenSys Software Inc., a blockchain

software company A software company is a company whose primary products are various forms of software, software technology, distribution, and software product development. They make up the software industry. Types There are a number of different types of soft ...

focusing on

-based tools and infrastructure.

Overview

MetaMask allows users to store and manage account

keys Key or The Key may refer to: Common meanings * Key (cryptography), a piece of information that controls the operation of a cryptography algorithm * Key (lock), device used to control access to places or facilities restricted by a lock * Key (ma ...

, broadcast transactions, send and receive

-based

cryptocurrencies A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it. It ...

and tokens, and securely connect to decentralized applications through a compatible

web browser A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on ...

or the

's built-in browser. Websites or other decentralized applications are able to connect,

authenticate Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicati ...

, and/or integrate other

smart contract A smart contract is a computer program or a transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objectives of smart contracts are the re ...

functionality with a user's MetaMask wallet (and any other similar blockchain wallet browser extensions) via

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side ...

code that allows the website to send action prompts, signature requests, or transaction requests to the user through MetaMask as an intermediary. The application includes an integrated service for exchanging

tokens by aggregating several decentralized exchanges (DEXs) to find the best exchange rate. This feature, branded as MetaMask Swaps, charges a service fee of 0.875% of the transaction amount. , MetaMask's browser extension had over 21 million monthly active users, according to

Bloomberg Bloomberg may refer to: People * Daniel J. Bloomberg (1905–1984), audio engineer * Georgina Bloomberg (born 1983), professional equestrian * Michael Bloomberg (born 1942), American businessman and founder of Bloomberg L.P.; politician and ...

History

MetaMask was created by

ConsenSys ConsenSys is a blockchain software technology company founded by Joseph Lubin and based in New York City. History Joseph Lubin founded ConsenSys in early 2015 as a software foundry to develop decentralized software services and applications ...

in 2016. Prior to 2019, MetaMask had only been available as a desktop

for

Google Chrome Google Chrome is a cross-platform web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macO ...

and

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and ...

browsers. Given the popularity of MetaMask among

cryptocurrency A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it. It ...

users, and its lack of an official

for several years, instances of malicious software posing as MetaMask became problematic for

Google Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...

in regulating its

Chrome Web Store Chrome Web Store is Google's online store for its Chrome web browser. As of 2019, Chrome Web Store hosts about 190,000 extensions and web apps. History Chrome Web Store was publicly unveiled in December 2010, and was opened on February 11, 20 ...

and

Google Play Google Play, also known as the Google Play Store and formerly the Android Market, is a digital distribution service operated and developed by Google. It serves as the official app store for certified devices running on the Android (operating sys ...

platforms. In one instance, Google Play unintentionally removed MetaMask's official

beta Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labi ...

app before reverting the decision a week later on January 1, 2020. Starting in 2019, MetaMask began releasing

versions for

closed beta A software release life cycle is the sum of the stages of development and maturity for a piece of computer software ranging from its initial development to its eventual release, and including updated versions of the released version to help impro ...

testing, followed by their official public release for

iOS iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that powers many of the company's mobile devices, including the iPhone; the term also include ...

and Android in September 2020. During October 2020, MetaMask Swaps, a built-in DEX aggregation service was added to the desktop extension. The product became available on mobile devices in March 2021.

Criticism

While MetaMask and other "

web3 Web3 (also known as Web 3.0) is an idea for a new iteration of the World Wide Web which incorporates concepts such as decentralization, blockchain technologies, and token-based economics. Some technologists and journalists have contrasted it w ...

" focused applications aim to decentralize control over

personal data Personal data, also known as personal information or personally identifiable information (PII), is any information related to an identifiable person. The abbreviation PII is widely accepted in the United States, but the phrase it abbreviates ha ...

and increase user privacy, critics have pointed to the potential for MetaMask's

to leak identifiable information to data collection networks and web trackers as a fundamental flaw.

References

{{Cryptocurrencies Ethereum Mobile applications Blockchain entities 2016 software Cryptocurrency projects