What is a Wei?

Wei is the smallest unit of Ether (ETH), the cryptocurrency used on the Ethereum network. Wei is named after Wei Dai, a computer scientist and cryptography pioneer who was an early influence on the development of cryptocurrency. Wei is used to represent very small amounts of Ether, allowing for transactions to be made with a high degree of precision and granularity.

In the Ethereum network, transactions are conducted in Wei rather than in ETH, as this allows for a high degree of flexibility and control over the size of transactions. For example, a transaction may be conducted for 100 Wei, which is a very small amount of Ether, or for 100,000,000,000 Wei, which is a much larger amount. This allows for transactions to be conducted with a high degree of precision and control, making it easier to manage the flow of Ether on the Ethereum network. Wei can be converted into ETH by multiplying the number of Wei by the conversion factor, which is 10^-18.

Simplified Example

An example of something that compares to Wei is a Satoshi, the smallest unit of Bitcoin (BTC). Just like Wei, a Satoshi is used to represent very small amounts of cryptocurrency and allows for transactions to be made with high precision and granularity. A Satoshi can be used to facilitate micropayments and is also used as a unit of investment, much like Wei. The key difference between Wei and Satoshi is that Wei is the smallest unit of Ether, while Satoshi is the smallest unit of Bitcoin.

Who Invented "Wei"?

The term "wei" in the context of cryptocurrency is named in honor of Wei Dai, a computer engineer renowned for his significant contributions to cryptography and cryptocurrencies. Dai is most notably recognized as the creator of the "b-money" cryptocurrency system, an early precursor to Bitcoin. In addition to his work on b-money, Dai is credited with the development of the Crypto++ cryptographic library and the co-proposal of the VMAC message authentication algorithm.


Gas fees: Gas fees are the cost of executing smart contracts on the Ethereum network, and they are measured in Wei. When a user wants to execute a smart contract, they must pay a fee in Wei, which is used to compensate the network's miners for their computational work.

Micropayments: Wei can be used to facilitate micropayments, which are very small payments that are less than a penny. Micropayments are often used in applications such as online games, where small amounts of money are charged for virtual goods or services.

Investment: Wei can be used as an investment, just like any other cryptocurrency. People can purchase Wei as a way to invest in the Ethereum network and benefit from the appreciation of its value over time. This investment can be made through cryptocurrency exchanges, which allow users to buy and sell Wei and other cryptocurrencies.

  • Ethereum Transaction: A digital contract that enables a user to send digital currency or other related assets like tokens, digital certificates, etc. over a distributed, decentralized, public ledger called the Ethereum blockchain.

  • Ethash: A proof-of-work consensus algorithm that is used by Ethereum and other blockchain networks.