Token Standard

A token standard works like a shared technical contract: it specifies which functions a token's smart contract must expose (transfer, balance lookup, approval, and so on) so that any wallet, exchange, or decentralized application built for that standard can interact with the token without custom integration work. Without this shared interface, every project would need its own bespoke code to support each new token, which is exactly the problem token standards were created to solve.

On Ethereum, standards are proposed as Ethereum Request for Comments (ERC) documents and refined through the broader Ethereum Improvement Proposal process before adoption. ERC-20, live since 2015, defines fungible tokens where every unit is identical and interchangeable, much like units of a currency. ERC-721 introduced non-fungible tokens with unique, non-interchangeable IDs for art, collectibles, and in-game items, while ERC-1155 lets a single contract manage both fungible and non-fungible assets together, which is useful in gaming and reduces deployment overhead.

Other blockchains maintain their own equivalents: BEP-20 on BNB Chain, TRC-20 on Tron, the Solana Program Library (SPL) standard on Solana, and BRC-20 for fungible tokens inscribed on Bitcoin. These standards are not interoperable at the protocol level: a token issued under one standard cannot move directly to a different blockchain without a bridge or an exchange facilitating the swap.

For users, the practical risk is contract quality rather than the standard itself. A token can follow a standard's interface correctly while still containing malicious or poorly audited code, so the standard guarantees compatibility, not safety.