Ethereum Name Service (ENS)

What Is the Ethereum Name Service?

The Ethereum Name Service (ENS) is a decentralized, open naming system built on the Ethereum blockchain. It translates long, complex addresses like 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 into simple, human-readable names like vitalik.eth. Think of it as the DNS (Domain Name System) of Web3: just as DNS maps domain names to IP addresses, ENS maps .eth names to blockchain addresses, content hashes, metadata, and more.

Originally specified in EIP-137 and launched on Ethereum mainnet in May 2017, ENS was created by Nick Johnson at the Ethereum Foundation. Unlike traditional domain registrars, ENS has no central authority that can seize or censor names. Ownership is enforced by Ethereum's consensus mechanism, and names are represented as ERC-721 NFTs that can be transferred, traded, or managed through any compatible wallet.

As of mid-2026, ENS has over 2.8 million registered .eth names and nearly 900,000 unique user addresses, making it the dominant naming standard in Web3.

How It Works

ENS operates through a layered architecture of smart contracts, each handling a distinct responsibility. Understanding these layers reveals how a simple name lookup actually works on-chain.

The Registry

The ENS registry is the core smart contract that maintains the authoritative mapping from name hashes to three pieces of information: the name's owner, its resolver address, and a time-to-live (TTL) caching hint. The registry does not store human-readable names directly. Instead, it uses a hashing algorithm called namehash to convert names into fixed-length, 32-byte identifiers called nodes.

The namehash algorithm works recursively. It splits a name by its dots, hashes each label individually with keccak256, then combines them from right to left:

namehash('') = 0x0000...0000
namehash('eth') = keccak256(namehash('') + keccak256('eth'))
namehash('vitalik.eth') = keccak256(namehash('eth') + keccak256('vitalik'))

This recursive structure means parent domain owners can create and manage subdomains. The owner of example.eth can create pay.example.eth without any external approval.

Resolvers

Resolvers are separate smart contracts responsible for translating names into actual records. When you look up vitalik.eth, the process involves two on-chain calls:

1. Query the registry for the resolver address associated with the namehash of "vitalik.eth"
2. Query that resolver contract for the specific record type you want (Ethereum address, content hash, text record, etc.)

This two-step design is intentional. By separating the registry from record storage, ENS allows anyone to deploy custom resolver contracts with new record types or resolution logic without modifying the core registry.

The Registrar

The .eth registrar handles the business logic of name registration and renewal. It uses a simple, first-come-first-served model with annual renewal fees based on name length:

Names with 1 or 2 characters cannot be registered. Shorter names cost more because the namespace is smaller and more valuable. Fees are paid in ETH at the current exchange rate, plus gas fees for the on-chain transaction.

Reverse Resolution

Forward resolution maps names to addresses. Reverse resolution does the opposite: it maps an Ethereum address back to its primary ENS name. This is defined in EIP-181 and works through a special .addr.reverse namespace. When a user sets their primary name, applications like block explorers and dApps can display "vitalik.eth" instead of a raw hex address.

Multi-Chain Address Resolution

ENS is not limited to Ethereum addresses. Through ENSIP-9, resolver contracts can store addresses for any blockchain using the SLIP-44 coin type standard. A single ENS name can resolve to an Ethereum address, a Bitcoin address, a Solana address, and more, all from the same record set.

Name Registration Process

Registering a .eth name involves a two-step commit-reveal process designed to prevent front-running:

1. Commit: the user submits a hash of the desired name and a secret value. This on-chain transaction locks in their intent without revealing the actual name.
2. Wait: a mandatory waiting period (currently one minute) prevents miners or other observers from seeing the name and registering it first.
3. Reveal: the user submits a second transaction with the actual name and secret. The registrar verifies the commitment matches, charges the registration fee, and assigns ownership.

After registration, the name is represented as an ERC-721 NFT in the user's wallet. Ownership can be transferred, and the name must be renewed before its expiration date to avoid losing it. Expired names enter a 90-day grace period before becoming available to others.

Use Cases

Wallet Identity and Payments

The most common use case is replacing raw addresses with memorable names for sending and receiving crypto. Instead of copy-pasting a 42-character hex string, users can type alice.eth in any ENS-compatible wallet. This reduces the risk of address poisoning attacks and simple copy-paste errors that can lead to permanent fund loss.

Decentralized Websites

ENS names can point to content stored on decentralized storage networks like IPFS or Arweave. By setting a content hash record, a name like mydapp.eth can serve a fully decentralized website that no single entity can take down. Browsers like Brave resolve these natively, while others can access them through gateways like eth.limo.

Social Identity

ENS names have become the de facto identity layer for Web3. Platforms, forums, and social applications display ENS names as usernames. Text records allow users to attach social profiles, avatars, email addresses, and other metadata to their name, creating a portable, self-sovereign identity across applications. This overlaps with the broader decentralized identity movement.

Subdomains for Organizations

Organizations can issue subdomains to members, customers, or products. A company owning acme.eth could issue alice.acme.eth to employees or pay.acme.eth as a payment endpoint. Subdomains can be created without additional registration fees, only requiring the gas cost of the on-chain transaction.

DNS Integration

ENS supports importing traditional DNS names (like .com or .xyz) into the ENS system. Owners of DNS domains can prove ownership via a DNSSEC proof and then use their existing domain as an ENS name, bridging the gap between traditional web infrastructure and Web3 naming.

Governance: The ENS DAO

ENS is governed by a decentralized autonomous organization (DAO) that controls protocol parameters, treasury funds, and upgrade decisions. The ENS DAO was established in November 2021 alongside the launch of the $ENS governance token.

The $ENS Token

The total supply of $ENS is 100 million tokens, distributed as follows:

• 50% to the DAO treasury (10% available at launch, remainder vesting linearly over 4 years from November 2021)
• 25% airdropped to addresses that had registered a .eth name before the snapshot on October 31, 2021
• 25% allocated to core contributors and ecosystem partners

Each $ENS token equals one vote. Token holders must delegate their voting power (either to themselves or another address) before a vote begins. Executable proposals require at least 100,000 $ENS delegated to the proposer. In August 2026, ENS tokenholders approved a proposal to transform the ENS Foundation into a full-time operating body with a five-member board and an approximately $65 million endowment.

ENSv2 and Protocol Evolution

ENS Labs originally proposed ENSv2 as a migration to a dedicated Layer 2 rollup (called "Namechain") to reduce registration costs and improve scalability. However, in February 2026, the team pivoted to deploying ENSv2 exclusively on Ethereum mainnet. The reason: Ethereum's own scaling upgrades (including gas limit increases from 30 million to 60 million) reduced ENS registration costs by roughly 99%, eliminating the primary motivation for an L2 migration.

Despite staying on L1, ENSv2 still includes significant protocol improvements: a redesigned registry architecture, a new ownership model, and improved name expiration mechanics. The upgrade reflects a broader trend in Ethereum infrastructure where L1 scaling gains are making certain L2 migrations less necessary. For context on how different Layer 2 approaches compare, see our Layer 2 comparison research.

Competition and Alternatives

ENS is the dominant Web3 naming system, but several competitors offer different tradeoffs:

ENS's strengths lie in its Ethereum-native composability, developer ecosystem, and decentralized governance. Unstoppable Domains appeals to users who prefer one-time payments and a broader selection of TLDs. Neither system resolves natively in mainstream browsers today, so both function primarily as crypto identity tools rather than traditional website addresses.

Other naming systems include the Nostr-based NIP-05 identifiers and BIP-353 DNS-based Bitcoin payment instructions, each targeting different use cases and communities.

Why It Matters

Human-readable naming is a fundamental usability layer for any network. Email would not have achieved mass adoption if users had to memorize IP addresses, and crypto faces the same challenge with raw blockchain addresses. ENS addresses this by providing a universal, censorship-resistant naming layer that works across wallets, dApps, and protocols.

For the broader crypto payments ecosystem, naming services reduce friction at the point of payment. Rather than scanning QR codes or pasting addresses, users can simply type a name. This is especially relevant for stablecoin merchant adoption, where simplifying the payment experience is critical for competing with traditional payment rails. In the Bitcoin ecosystem, similar efforts like Lightning Addresses and BIP-353 tackle the same problem for Bitcoin-native payments.

Risks and Considerations

Name Squatting

Like traditional DNS, ENS faces name squatting: speculators register popular names hoping to resell them at a markup. Unlike DNS, ENS has no formal trademark dispute mechanism. The annual renewal model mitigates this somewhat by imposing ongoing holding costs, but valuable short names still attract speculative registration.

Centralization Risks

While ENS is decentralized at the protocol level, the root node of the ENS registry is controlled by a multisig held by trusted keyholders. This multisig can, in theory, replace the .eth registrar or modify top-level domain ownership. The DAO has discussed plans to further decentralize or lock down root node control, but as of 2026, this centralization vector remains.

Ethereum Dependency

ENS is deeply tied to Ethereum. If Ethereum experiences prolonged congestion, censorship at the validator level, or a critical security incident, ENS resolution could be disrupted. While ENS supports multi-chain address records, the registry and resolver infrastructure itself runs exclusively on Ethereum.

Phishing and Social Engineering

Visually similar names (like vitaIik.eth with a capital I instead of lowercase L) can be used for phishing attacks. ENS names support Unicode characters through UTS-46 normalization, but homoglyph attacks remain a risk. Users should always verify the full resolved address before sending large transactions.

Renewal and Expiry Risks

Unlike one-time purchase models, ENS names require annual renewal. If a user loses access to their wallet, forgets to renew, or misses the 90-day grace period, their name becomes available for anyone to register. High-value names are actively monitored by bots that register them immediately upon expiration.

This glossary entry is for informational purposes only and does not constitute financial or investment advice. Always do your own research before using any protocol or technology.