What Is an ERC-20 Token?
Last Updated: June 2026
The ERC-20 standard is the technical backbone of the modern token economy. Introduced on the Ethereum blockchain, it defines a common set of rules that any fungible token must follow, making tokens predictably compatible with wallets, decentralized applications, and exchanges. From stablecoins like USDT to governance tokens powering DeFi protocols, virtually every major token you encounter on a crypto exchange today was built using this standard. Understanding what ERC-20 means — and why it matters — is foundational knowledge for anyone participating in decentralized markets or spot trading.
What Does ERC-20 Actually Mean?
ERC stands for Ethereum Request for Comment, a process borrowed from early internet standards development. The "20" is simply the proposal number assigned when developer Fabian Vogelsteller submitted the specification to the Ethereum GitHub repository in November 2015. Before this standard existed, developers creating tokens on Ethereum each wrote their own custom logic with no guarantee that their token would work with other contracts or applications. The result was fragmentation — each token required custom integration work before it could be listed or used anywhere.
ERC-20 solved this by defining a mandatory interface: a set of six functions and two events that every compliant token contract must implement. Once deployed, any ERC-20 token is automatically compatible with any wallet or protocol that speaks the same interface. This standardization is what enabled the 2017 ICO boom, the rise of DeFi, and the proliferation of thousands of tokens that can be traded across different platforms without bespoke integration.
The Six Core Functions of the ERC-20 Standard
The power of ERC-20 lies in its simplicity. The standard mandates exactly six functions:
- totalSupply — Returns the total number of tokens in existence for that contract.
- balanceOf — Returns the token balance held by a specific wallet address.
- transfer — Moves tokens directly from the caller's address to a recipient address.
- transferFrom — Allows an approved third party (such as a smart contract) to move tokens on behalf of an owner.
- approve — Grants a third-party address permission to spend up to a specified amount of tokens on the owner's behalf.
- allowance — Returns the remaining number of tokens that an approved spender is still permitted to withdraw from an owner's account.
Two optional events — Transfer and Approval — allow applications to listen for and react to token movements in real time. Together, these functions and events define the complete operational surface of an ERC-20 token.
ERC-20 vs. Other Token Standards
As the ecosystem matured, developers built on the ERC-20 foundation and introduced new standards for different use cases. Here is how ERC-20 compares to the most common alternatives:
| Standard | Type | Primary Use Case | Fungible? | |----------|------|-----------------|-----------| | ERC-20 | Fungible token | Currencies, stablecoins, governance tokens | Yes | | ERC-721 | Non-fungible token | Digital art, collectibles, unique assets | No | | ERC-1155 | Multi-token | Gaming items, mixed asset batches | Both | | ERC-4626 | Tokenized vault | Yield-bearing DeFi positions | Yes |
ERC-20 remains the dominant standard for assets intended to function as currencies or financial instruments. Its widespread adoption means the largest liquidity pools, most audited codebases, and deepest exchange integrations all center on ERC-20 compatible assets. When you hold USDT, LINK, UNI, or AAVE, you are holding ERC-20 tokens.
Trading ERC-20 Tokens on EVEDEX
EVEDEX is a decentralized exchange built to give traders access to a wide range of digital assets, including the most actively traded ERC-20 tokens. Because ERC-20 tokens share a common interface, integrating them into a decentralized order book or liquidity mechanism is straightforward — and EVEDEX takes full advantage of this.
On EVEDEX, traders can access spot trading pairs involving ERC-20 stablecoins and major tokens, as well as leverage trading on crypto derivatives. Since EVEDEX is non-custodial, you retain control of your private keys throughout the trading process — your tokens remain in your wallet until a trade is settled on-chain. This is a meaningful distinction from centralized platforms, where your ERC-20 tokens are held by the exchange during the period you keep funds deposited.
For crypto futures traders, ERC-20 stablecoins like USDT are commonly used as collateral, making familiarity with the standard practically necessary. EVEDEX supports this workflow, allowing users to post ERC-20 margin and manage positions without relying on a centralized custodian.
Understanding ERC-20 is not just academic. It directly affects how you connect your wallet, how approvals work when interacting with DeFi protocols, and why certain tokens can be traded on more platforms than others. The standard's longevity since 2015 speaks to how well it was designed — and why it continues to underpin most of the assets in active use today.
