Blockchain domains are decentralized, blockchain-based identifiers that replace wallet addresses or traditional URLs. They emerged around 2017, starting with services like ENS, as a way to simplify crypto interactions.
Their adoption grew between 2019 and 2021, driven by the rise of Web3, DeFi, and NFTs, as users sought ownership, censorship resistance, and alternatives to traditional DNS.
Decentralised domain names can replace the names of cryptocurrency wallets such as 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa with simple, easy-to-remember addresses on the blockchain such as mywallet.eth.
A reverse record is the on-chain mapping from a blockchain address to its human-readable domain name. In systems like ENS it designates a Primary Name for an address so apps can show alice.eth instead of 0x… and pull profile data such as avatar and text fields. Correct setup requires forward confirmation, meaning the name must resolve back to the same address to avoid spoofing. It is optional and affects display and identification only, not permissions or payments, and similar reverse lookups exist in other Web3 naming systems to retrieve a name from an address.
A Web3 naming protocol is an on-chain system that turns human-readable names into blockchain identifiers and resources. It defines how names are created, owned, renewed, and transferred, and how records resolve to wallet addresses, content, or services. Names are usually tokenized as NFTs, globally unique within their namespace, and can delegate subdomains that compatible wallets and dApps can resolve.
Owned as crypto assets, blockchain domains can technically be used for payments, identity, or hosting content without central control. However, such uses are in practice little developed, blockchain domains being almost exclusively defensive, speculative or cybersquatting registrations. In addition, these decentralized domains create numerous situations of confusion and conflict, since any provider can create its extension on the blockchain, even if it already exists on the blockchain or in the ICANN root.
Every blockchain domain is an NFT with naming utility, but most NFTs are not domains.