Q: What happens if I enter an invalid Ethereum address?
The tool validates that the address is exactly 42 characters long (including the 0x prefix) and contains only valid hexadecimal characters (0-9, a-f, A-F). If the address is invalid, an error message will be displayed.
Q: Is my address data secure?
Yes. All processing happens entirely in your browser using client-side JavaScript. No address data is ever sent to any server.
Q: What is the difference between a checksummed and non-checksummed address?
A non-checksummed address is all lowercase (e.g., 0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed). A checksummed address uses mixed-case letters based on the Keccak-256 hash (e.g., 0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed). Both represent the same address, but the checksummed version provides error detection.
Q: Can I use this tool to validate contract addresses?
Yes. EIP-55 checksums apply to all Ethereum addresses, including externally owned accounts (EOA) and smart contract addresses. The checksum format is identical for both types.
Q: Does this tool support other blockchain networks?
EIP-55 checksums are compatible with all EVM-compatible chains, including Polygon, BNB Chain, Arbitrum, Optimism, Avalanche C-Chain, and others. Any blockchain that uses the same 20-byte address format as Ethereum can use EIP-55 checksums.
Q: How does the EIP-55 algorithm work internally?
The algorithm takes the lowercase hex address (without 0x), computes its Keccak-256 hash, then iterates through each character. If the character is a letter (a-f) and the corresponding nibble in the hash is 8 or greater (0x8-0xF), it is capitalized. Otherwise, it remains lowercase. Numbers (0-9) are unchanged.