ENS (Ethereum Name Service)

How ENS works

ENS is a set of smart contracts on Ethereum that maintains a hierarchical mapping from human-readable names to various target data:

• Wallet addresses — vitalik.eth resolves to Vitalik Buterin's primary Ethereum address.
• Content hashes — IPFS or Swarm content addresses, allowing a .eth name to point to a website or file.
• Other text records — email, Twitter, GitHub, avatars, descriptions.
• Subdomains — owners of name.eth can create subdomain.name.eth and configure them independently.

ENS names are themselves NFTs (ERC-721 tokens), which means they're transferable, can be traded on NFT marketplaces, and inherit standard NFT infrastructure.

Registration

The mechanic:

1. A user picks an available name and pays a fee in ETH.
2. The fee is calculated by character count and registration period — shorter names cost more, longer registrations cost more.
3. The name is registered to the user's wallet for the chosen duration.
4. The user configures records (target address, etc.) for the name.
5. The name auto-renews if the user keeps paying; otherwise it expires after a grace period and becomes available to others.

Annual renewal fees are modest for typical names ($5-50/year for names of 5+ characters); shorter names cost more (3-character names ~$640/year, 4-character ~$160/year, 5+ characters ~$5/year).

Why ENS matters

Two main use cases:

• Easier transactions. Sending to vitalik.eth is much harder to mistype than sending to 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045. Every major Ethereum wallet (MetaMask, Rabby, Coinbase Wallet) supports ENS resolution.
• Onchain identity. A user's ENS name becomes a portable identity that follows them across applications. Twitter (now X) verified ENS-linked profiles for a period; many onchain social apps use ENS as the default display name.

This is the closest thing crypto has to a unified identity layer, and it works without requiring centralized issuance or user registration in every application separately.

ENS DAO

ENS launched a DAO and governance token (ENS) in November 2021 via airdrop to historical ENS users. The airdrop's distribution is studied as one of the best-designed in crypto — generous to long-term users, fair across name-holders.

The DAO governs:

• Pricing for new registrations — what character lengths cost what.
• Treasury management — multi-million-dollar treasury supports development and ecosystem.
• Future protocol upgrades.

The governance has been notably professional and active relative to many DAOs.

ENS and the namespace

Two components of the namespace:

• Top-level .eth — the original ENS namespace. Sold as 99-year leases historically; now perpetual annual renewal.
• DNS integration — ENS supports importing existing DNS domain names (like example.com). The owner of the DNS domain can configure their ENS records.

This DNS bridge means crypto-savvy domain owners can use existing names as ENS records without losing their crypto identity to a new naming system.

L2 expansion

Originally, ENS lived only on Ethereum mainnet, with high gas costs for registration and updates. Recent developments:

• CCIP-Read — a protocol for resolving ENS data stored off-chain or on L2s, enabling cheaper and more flexible resolution.
• L2 ENS support — ENS works seamlessly across L2s (Arbitrum, Optimism, Base), with the same name resolving correctly regardless of which chain the wallet is on.
• Subdomain delegation to L2s — ENS owners can issue subdomains that live entirely on L2, dramatically reducing per-subdomain costs.

The result: ENS scales from "expensive primary identity" to "general-purpose decentralized DNS for crypto," with applications creating ENS-based identities for users without high cost.

Comparison with alternatives

Several other naming systems have emerged:

• Unstoppable Domains — runs on multiple chains; one-time payment rather than annual renewal; less Ethereum-native than ENS.
• Lens Protocol handles — @username.lens for the Farcaster-competing social network on Polygon.
• Solana Name Service — .sol names on Solana.
• Various L2-specific naming — some L2s have their own naming services.

ENS dominates Ethereum-native usage and is the de facto standard for "crypto identity" on EVM chains. Other systems serve specific ecosystems but haven't achieved the cross-application traction ENS has.

Pitfalls

A few things ENS users should know:

• Wrong configuration loses funds. Setting an ENS record incorrectly can cause sends to go to wrong addresses. Verify resolution carefully for important names.
• Squatting. Many short, common names were registered early and now trade for enormous prices on secondary markets. Most desirable names aren't available cheaply.
• Phishing via similar names. vitaIik.eth (capital "I" replacing lowercase "l") looks identical at a glance. Verify carefully.
• Privacy implications. Linking your ENS name to a wallet makes your transactions publicly traceable to your identity in a way that anonymous addresses don't. Use deliberately.