Wallet Checksum Generator

EIP-55 defines a mixed-case checksum for Ethereum addresses. The algorithm: take the lowercase 40-char hex address, hash it with Keccak-256, then capitalize each character where the corresponding hash nibble is >= 8. This creates a unique representation that changes if any character is wrong.

Wallets use checksummed addresses to help users spot typos before sending funds. This tool validates address format and applies checksum encoding. Note: we use SHA-256 as an approximation since the browser lacks Keccak-256; for production, use ethers.js.

A valid Ethereum address is 40 hexadecimal characters, optionally prefixed with 0x. This tool checks the format and reports valid/invalid. It accepts input with or without 0x. Invalid inputs include wrong length (e.g., 42 chars with 0x), non-hex characters, or empty input.

Validation is format-only — we don't verify on-chain existence or balance. Use Etherscan or similar to check if an address has been used.

True EIP-55 uses Keccak-256 (SHA3). The Web Crypto API provides SHA-256, SHA-384, SHA-512, and SHA-1, but not Keccak. This tool uses SHA-256 to demonstrate the checksum concept: hash the address, use nibbles to decide capitalization. The output will differ from canonical EIP-55. For correct EIP-55 encoding, use ethers.js getAddress() or the Keccak256 Generator with an external library.