Token Standard
A set of rules that defines how tokens are created, transferred, and interact with other contracts on a blockchain.
What is Token Standard?
A token standard is a technical specification — typically defined as an Ethereum Improvement Proposal (EIP) or similar governance document on other chains — that establishes a common interface for creating and managing tokens on a blockchain. Token standards define the functions and events a token contract must implement, ensuring interoperability with wallets, exchanges, and other smart contracts that rely on a predictable interface. The most widely adopted standards are ERC-20 (fungible tokens — every unit is identical and interchangeable, like USDC or UNI), ERC-721 (non-fungible tokens — each token has a unique ID, like an NFT artwork), and ERC-1155 (multi-token standard supporting both fungible and non-fungible tokens in a single contract). Complying with a standard means any ERC-20 wallet or DEX can automatically handle the token without custom integration.
Example
Tether's USDT on Ethereum is an ERC-20 token. By conforming to the ERC-20 standard, USDT works automatically with MetaMask, Uniswap, Aave, and thousands of other applications — no custom code required on their part. Developers simply check that the token's contract implements the standard transfer(), balanceOf(), and approve() functions.