What Is a Token Standard Like ERC-20?
Thousands of different tokens can sit in the same wallet and trade on the same exchanges without custom code being written for each one, and that consistency comes down to a shared technical agreement most users never see.
The short answer
A token standard is a published set of technical rules that defines how a token behaves on a given blockchain, including how balances are tracked, how transfers are executed, and how other applications can read basic information about the token. Ethereum’s ERC-20 is the best-known example, used for tokens that behave like ordinary transferable assets. Because every token built to a shared standard implements the same basic functions in the same way, wallets, exchanges, and other applications can support new tokens automatically rather than needing custom integration work for each one.
Why a shared standard matters
Before common standards existed, developers building a new token had no guarantee that wallets or exchanges would know how to interact with it, since each token could define transfers, balances, and other behavior however its creator chose. A standard solves this by acting like a common interface: any application that already knows how to work with one standard-compliant token automatically knows how to work with every other token built to that same standard. This is part of why a new token can often be added to a wallet or listed on an exchange with minimal custom development, and it’s closely related to why new crypto projects publish detailed whitepapers describing exactly which technical standards their token follows.
What a standard typically defines
- Balance tracking. A consistent way to check how many units of the token a given address holds.
- Transfer functions. A standard method for moving tokens from one address to another, which every compliant wallet and exchange knows how to call.
- Approval mechanisms. A way for a token holder to authorize another address or application to move a specific amount of tokens on their behalf, commonly used by decentralized applications.
- Basic metadata. Information such as the token’s name, abbreviation, and how many decimal places it supports.
How standards differ from one another
Not every token standard serves the same purpose. ERC-20 describes tokens that are interchangeable with one another, meaning any one unit is identical in value and function to any other unit of the same token, which fits currencies, reward points, or governance tokens. Other standards exist specifically for non-interchangeable tokens, where each individual token is unique, which underlies most NFTs and connects to how NFTs are taxed differently from interchangeable tokens. A blockchain can support multiple standards simultaneously, and the standard a developer chooses depends entirely on whether the tokens being created are meant to be identical units or unique items.
How this connects to the wallet and blockchain layers underneath
A token standard operates on top of a blockchain’s more basic infrastructure. The blockchain itself provides the ledger and the consensus process that confirms transactions are valid, nodes across the network independently verify that those transactions follow the rules, and each transfer relies on public key cryptography to confirm the sender actually authorized it. The token standard simply defines a consistent way for smart contracts to represent ownership and transfers within that system. A token isn’t a separate blockchain of its own; it’s a set of rules implemented as code that runs on an existing blockchain’s infrastructure.
Risks worth keeping in mind
Adopting a standard doesn’t guarantee a token is safe or legitimate. A token can technically follow a standard’s rules correctly while still being poorly designed, thinly traded, or created for a fraudulent purpose, so compliance with a standard says nothing about a token’s value or trustworthiness. Smart contract code implementing a standard can also contain bugs, and any token transfer, once confirmed on the blockchain, is irreversible. As with crypto broadly, holdings are not covered by FDIC or SIPC protection, so the usual cautions around volatility and security still apply regardless of which standard a token follows.
What to weigh
Understanding that a token standard is purely a technical agreement, not a certification of quality or safety, helps put claims about “standard compliance” in proper context. It explains the plumbing that lets a wallet display a new token correctly, but it says nothing about whether that token is worth holding.