When people first encounter ENS, they often describe it as "blockchain DNS." That analogy is useful for a quick explanation, but it obscures important differences in how the two systems work, who controls them, and what you can build with them. Here's a clear-eyed comparison for developers who work across both.
What DNS Does
The Domain Name System is a hierarchical, globally distributed database that maps domain names like github.com to IP addresses. It's operated by a network of authoritative nameservers, coordinated by ICANN, and cached by resolvers worldwide. DNS was designed in the 1980s for reliability and speed — and it achieves both, serving billions of queries per second.
DNS records include A records (IPv4 address), AAAA records (IPv6), CNAME (alias), MX (mail), TXT (arbitrary text), and more. Records are managed through your domain registrar (GoDaddy, Namecheap, Cloudflare, etc.).
How ENS Works Differently
ENS stores name records in smart contracts on Ethereum. Instead of mapping names to IP addresses, it maps names to:
- Ethereum wallet addresses (and addresses on 100+ other chains)
- IPFS, IPNS, Arweave, or Swarm contenthashes (for decentralized websites)
- Arbitrary text records (avatar, email, social handles, description)
- ABI data (for smart contract interfaces)
There is no central registrar. Anyone can register a .eth name by interacting directly with the ENS contracts. Ownership is represented as an ERC-721 or ERC-1155 NFT, transferable peer-to-peer.
Technical Differences
- Storage: DNS records live on authoritative nameservers. ENS records live in Ethereum smart contracts (onchain) or behind CCIP-Read gateways (offchain).
- Ownership model: DNS names are leased annually. ENS names are owned as NFTs with yearly renewal prices. Subnames can optionally never expiry. The owner is the NFT holder.
- Update mechanism: DNS updates propagate via TTL-based caching (minutes to 48h). ENS updates are onchain transactions, final once confirmed.
- Censorship resistance: DNS can be seized, suspended, or blocked at the registrar, registry, or ISP level. ENS names cannot be unilaterally revoked while the owner holds the NFT.
- Resolution speed: DNS resolution is microseconds (cached). Raw ENS resolution requires Ethereum RPC calls (~100–500ms). With a caching layer like Resolvio, this drops to <50ms.
- Cost: DNS registration is $10–20/year. ENS registration involves gas fees and a registration fee (currently ~$5/year for 5+ character names).
- Programmability: DNS is read-only from the application layer. ENS resolvers are smart contracts — resolution logic can be fully customized.
DNS Names in ENS
ENS also supports traditional DNS names via DNSSEC. If you own yourapp.com, you can claim it in ENS by setting a specific TXT record in your DNS that proves ownership. Once claimed, yourapp.com can have an ENS resolver and store onchain records — your DNS name becomes a Web3 identity too.
When to Use Each
- Use DNS for: hosting websites, email delivery, CDN routing, any application that relies on the global internet infrastructure.
- Use ENS for: wallet payment addresses, onchain identity, NFT-gated access, decentralized website hosting (via IPFS contenthash), Web3 login (with ENS as the identifier).
- Use both when you want your users to have a single name (
yourapp.com) that works for both traditional web traffic and onchain payments.
Resolving Both with Resolvio
Resolvio resolves both .eth names and DNS names that have been registered in ENS, through the same API endpoint. Your application code doesn't need to know which type of name it's resolving.
# .eth name
curl https://api.resolvio.xyz/ens/v2/resolve/vitalik.eth
# DNS name with ENS resolver
curl https://api.resolvio.xyz/ens/v2/resolve/nick.xyz