ENS is the Ethereum Name Service. It swaps a long wallet address like 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 for something you can read and say out loud, like vitalik.eth. You register a name and point it at your wallet. Anyone who knows the name can then send you crypto or look up your profile without handling the full address.

Your name stores an ETH Address record pointing at your wallet, and you can add address records for other chains too, such as Bitcoin and Solana. To make yourname.eth appear in apps instead of your 0x address, set it as your primary name, the name apps show for your wallet: set your primary name (Testnet: Set your primary name).

Think of your name as a container, and the records as what sits inside it: avatar, social handles, wallet addresses, a decentralised website, and custom text records. Apps that read ENS pick this profile up when you connect, so you need no separate profile per service. Some apps also support Sign-In with Ethereum: you sign in with your wallet instead of a password. Because your wallet can carry a name, what the app greets you with is your name. See Edit your ENS profile (Testnet: Edit your ENS profile).

Point yourname.eth at a website hosted on a decentralised network, using the Content Hash record. Name and hosting then both sit outside any single company's servers. See Add a decentralised website to your ENS name. Supported networks:

Any name you own can issue subnames, like pay.yourname.eth or alice.yourteam.eth. Each carries its own records and can point at a different wallet. Communities use them to give members a shared identity; you can use them to label your own wallets. See Create or delete subnames (Testnet: Create a subname).

Register a .eth name at app.ens.domains. Search for the name you want; if it is available, register it there and then. You pay per year, in ETH on Ethereum Mainnet, plus gas (the network fee). The name is then yours to manage: edit its records, transfer it, or renew it before it expires. See Register a .eth name and Pricing & Fees.

On ENSv2 Testnet the apps are app.ens.dev and explorer.ens.dev, both on Sepolia. See Register a .eth name (Testnet).

In plain terms: you register a name, and ENS keeps a public note of which wallet and which details that name points at. Any app can read that note, which is why people can send to your name instead of a long address, and why your profile follows you between apps. Underneath, two contracts do the bookkeeping. The registrar decides whether yourname.eth is available, takes the fee and issues you the ownership NFT. The registry records who owns each name and which resolver it uses: the contract holding the name's records. When someone sends crypto to your name, their wallet asks the registry for the resolver, and the resolver answers with your address. You can change your records at any time; the name stays the same even when the wallet behind it changes. ENS also works with DNS names you already own, such as a .com: see What TLDs are supported?

ENS is a decentralised protocol governed by the ENS DAO, a community that votes on proposals. No single company owns or controls it. Names are held onchain as NFTs, and a name stays yours for as long as you keep it registered. See Official ENS websites, apps, and tools and The story of ENS.

ENSv1 is the version running on Ethereum Mainnet; every .eth name registered at app.ens.domains is an ENSv1 name. ENSv2 rebuilds the protocol so that each name can have its own registry, for its subnames, with finer control over who can do what. ENSv2 will run on Ethereum Mainnet too, once it launches. For now its contracts and apps are on the Sepolia test network, and Sepolia names are test names that do not carry over to Ethereum Mainnet.