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 capita ...

blockchain. It allows users to access their Ethereum wallet through a browser extension or

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 d ...

, 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, broadcast transactions, send and receive

-based cryptocurrencies 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 o ...

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 indicatin ...

, and/or integrate other smart contract 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 websites use JavaScript on the client side for webpage behavior, of ...

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 m ...

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 browser extension for Google Chrome 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 ...

browsers. Given the popularity of MetaMask among cryptocurrency users, and its lack of an official

for several years, instances of

malicious software Malware (a portmanteau for ''malicious software'') is any software intentionally designed to cause disruption to a computer, server, client, or computer network, leak private information, gain unauthorized access to information or systems, ...

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 sy ...

platforms. In one instance, Google Play unintentionally removed MetaMask's official beta 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 and increase user privacy, critics have pointed to the potential for MetaMask's browser extension 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