did:ethr vs did:ens: Verifiable Identifier vs Human-Readable Name

did:ethr excels at providing a decentralized, cryptographically verifiable identity anchored to an Ethereum address. Its DID document is a smart contract (like a ERC-1056 registry), enabling direct on-chain verification and integration with Ethereum's security model. For example, a user's DID can be resolved directly from their public key, and its status can be checked via a transaction on Ethereum or a compatible L2 like Arbitrum or Optimism, inheriting their high security guarantees.

did:ens takes a different approach by mapping a human-readable .eth name to a DID document. This strategy prioritizes user experience and discoverability, as names like alice.eth are far more memorable than a cryptographic hash. The trade-off is a dependency on the ENS registry's resolution system and the associated annual renewal fees, introducing a small recurring cost and a centralized point of lookup (though the registry itself is decentralized).

The key trade-off: If your priority is maximizing cryptographic security, self-sovereignty, and direct on-chain verifiability for applications like decentralized credentials (Verifiable Credentials) or access control, choose did:ethr. If you prioritize user-friendly onboarding, human-readable identifiers, and integration with the broader ENS ecosystem (like avatar metadata and subdomain management), choose did:ens.

did:ethr excels at providing a self-sovereign, portable, and cryptographically verifiable identity because it is built directly on the Ethereum Virtual Machine (EVM) and uses standard EIP-712 signatures. For example, its reliance on a simple smart contract registry (like the EthereumDIDRegistry) and public key resolution makes it the de facto standard for enterprise SSI projects and high-assurance use cases like verifiable credentials, where decentralization and cryptographic proof are non-negotiable. Its compatibility with the W3C DID Core specification ensures it integrates seamlessly with the broader decentralized identity stack, including verifiable data registries (VDRs).

did:ens takes a different approach by bundling a human-readable name with identity resolution. This results in a powerful trade-off: you gain immense usability and discoverability (e.g., alice.eth), but you inherit the architectural constraints and costs of the ENS system. The primary identifier is the ENS name, with DID Document resolution layered on top via the ENS resolver contract. This creates a dependency on ENS's specific governance, renewal fees (approximately $5/year for a .eth name), and its underlying L1/L2 infrastructure, which can impact portability and long-term sovereignty compared to a pure public-key model.

The key trade-off: If your priority is maximal decentralization, cryptographic portability, and compliance with SSI paradigms for enterprise or high-stakes applications, choose did:ethr. It is the tool for building trust layers. If you prioritize end-user experience, human-readable branding, and seamless integration with the existing ENS ecosystem (like decentralized websites and avatar metadata), choose did:ens. It is the tool for user-facing identity within the Ethereum application landscape. For many projects, the optimal strategy is to use both: an did:ethr identifier as the cryptographic root of trust, with an ENS name as a friendly alias for discovery.