There are several of token standards that currently exist on the Ethereum blockchain, each with their own rules and purpose. It must be noted that Ether (ETH), the native token of the Ethereum blockchain, cannot be labelled accordingly to any of the following standards. This is as ETH was designed during the inception of the Ethereum network, prior to the implementation of any of these standards.

Proposed in EIP-20 by Ethereum dApp developer Fabian Vogelstellar, ERC-20 is the current standard for fungible tokens. These tokens can be easily transferred between accounts through smart contract technology, and are flexible in functionality. Some popular examples of existing ERC-20 tokens include:

Proposed in EIP-721 by a team of Ethereum contributors including: William Entriken, Dieter Shirley, Jacob Evans, and Natassia Sash, ERC-721 is a popular Non-Fungible Token (NFT) standard. All NFTs have a unique tokenId, which can be utilised by dApps. This means that you can define a metadata URL for all NFTs. For example, a dApp may convert the tokenId of a NFT into a picture. As a result, the ERC-721 is currently a common standard for profile picture and collectible item NFTs. Some popular examples of existing ERC-721 tokens include:

Proposed in EIP-1155 by a team of Ethereum contributors including Witek Radomski, Andrew Cooke, Philippe Castonguay, James Therien, Eric Binet, and Ronan Sandford, ERC-1155 is another prevalent standard that aims to offer a medium between ERC-20 and ERC-721. Multiple ERC-1155 tokens can be managed in a single transaction, much like ERC-20 tokens, thus allowing for greater efficiency in comparison to ERC-721 tokens. However, ERC-1155 tokens are designed such that if there is only 1 token in supply, it is treated like a NFT and thus can have a defined metadata. Thus, ERC-1155 is favoured by blockchain games, such as:

Proposed in EIP-777 by a team of Ethereum contributors including Jacques Dafflon, Jordi Baylina, and Thomas Shababi, ERC-777 aimed to improve on the ERC-20 standard through the ‘hooks’ function introduced in ERC-1820. Whenever a token is sent or received through a smart contract with a hook, the hook allows the smart contract to react to that token within a single transaction, including allowing for the rejection of that token. This hook, however, rendered tokens in the ERC-777 standard vulnerable to attack and phishing. Thus, ERC-777 as a standard has been largely depreciated and it is recommended to use ERC-20 in its stead.

Proposed in EIP-4626 by Joey Santoro, t11s, Jet Jadeja, Alberto Cuesta Cañada, and Señor Doggo, ERC-4626 acts as a standard for tokenised yield-bearing vaults that use ERC-20, thus streamlining the yield processes for applications. Thus, ERC-4626 operates as an extension to ERC-20, involving an interface that allows developers to customise the specifications of the vault with ease.

Proposed in EIP-223 by Dexaran, ERC-223 aimed to improve on the ERC-20 standard through addressing one of its major flaws: that ERC-20 tokens sent to a smart contract that did not support ERC-20 would be then be lost. To do this, ERC-223 sent to a smart contract that is not designed to receive ERC-223 tokens will be returned to the sender, as the recipient smart contract can also detect when ERC-223 tokens are being sent. Aside from this, ERC-223 retains all the functionalities of ERC-20. However, as ERC-223 is incompatible with ERC-20, there has been little adoption of this standard.