What are crypto domains and how do they work?

Crypto domains are human-readable names, such as alice.eth or alice.crypto, that are stored on a blockchain and point to wallet addresses, websites or other records. Many are issued as NFTs, so the owner holds the name in a crypto wallet and can transfer it like any other token. Two widely used naming systems are Ethereum Name Service (ENS) and Unstoppable Domains.

How do NFT domains work?

A crypto domain is a record in a smart contract. The owner can attach data to it, most often a wallet address, so someone sending funds can type the name instead of a long string of characters. A wallet or app that supports the naming system looks up the record on-chain and finds the address.

Unstoppable Domains says its names are NFTs held in the owner's wallet, and that the company cannot change, deactivate or transfer a domain's records without the owner's permission. Its docs say new names are minted and managed on Polygon, a network where it says users pay no minting, renewal or gas fees, and that names can be moved there from Ethereum and Zilliqa. For background on the token side, see what is an NFT.

What is the difference between ENS domains and Unstoppable Domains?

The biggest practical difference is renewal. ENS .eth names belong to the owner for the period paid for. After expiry there is a 90-day grace period in which the name can still be renewed, then a 21-day window in which anyone can register it at a falling premium, according to ENS support. Unstoppable Domains says a name it sells stays with the owner for life with no renewal fees.

They also use different endings. ENS centers on .eth on Ethereum, as explained in our guide to ENS. Unstoppable Domains has offered endings such as .crypto, .x, .nft, .dao, .wallet and .bitcoin.

Do .crypto domains work in a normal browser?

Not by default. Most crypto domain endings are not part of ICANN's root, the system that makes .com and .org work everywhere. They resolve only where a wallet, app or browser adds support. Brave, for example, resolves ENS .eth names and several Unstoppable Domains endings, mainly on desktop and Android, and says it may disable an ending if it conflicts with another namespace.

What are the risks of web3 domain names?

Without a central authority, two providers can sell the same ending. In October 2022, Unstoppable Domains switched off its .coin ending after finding another project had sold .coin names since 2014, Domain Incite reported. More than 116,000 names stopped resolving in supported apps even though owners still held the NFTs.

The relationship with ICANN is also unsettled. In August 2026, Domain Name Wire reported that Unstoppable Domains dropped plans to apply for official versions of nine endings, including .crypto, .wallet and .nft, after an ICANN working group proposed rules that would require every integrated name to be registered and paid for in the traditional system. As of October 2026, those endings remain blockchain-only names.