✅ EIP-55 Ethereum Address Checksum
Check whether an Ethereum address has a valid EIP-55 checksum, and convert any address to its correct mixed-case form — the standard way wallets catch mistyped addresses.
Checksummed (EIP-55)
0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed
EIP-55 encodes a checksum in the letter casing of a hex address — each letter is uppercased when the matching nibble of the address’s Keccak-256 hash is ≥ 8. Wallets use it to catch typos. This validates and converts any address, entirely in your browser. Public addresses only — never paste a private key or seed phrase anywhere.
How the eip-55 ethereum address checksum works
EIP-55 hides a checksum in the letter casing of a hex address: each alphabetic character is uppercased when the corresponding nibble of the address’s Keccak-256 hash is 8 or greater. Paste an address and the tool tells you whether its casing is a valid checksum (a strong signal it wasn’t mistyped) and gives you the correctly-checksummed version to copy.
A safety-oriented developer utility for PUBLIC addresses only. It never handles private keys, seed phrases or funds, performs no transactions, and gives no financial advice — never paste a private key or seed phrase into any tool.
Frequently asked questions
What is an EIP-55 checksum?
A way of encoding a checksum into the upper/lowercase pattern of an Ethereum address’s hex letters, defined in EIP-55. A wallet can then detect a single mistyped character, because the casing would no longer match the address’s Keccak-256 hash.
How do I know if an address is valid?
Paste it here: if the mixed-case matches EIP-55, it’s a valid checksum (unlikely to be mistyped). An all-lowercase or all-uppercase address has no checksum to verify — this tool will give you the correct checksummed form.
Does a valid checksum mean the address is “safe”?
It only means the address is well-formed and probably not mistyped. It says nothing about who controls the address or whether it’s trustworthy — always verify the recipient through a trusted channel.
Why are some letters uppercase?
Each hex letter (a–f) is uppercased when the matching nibble of the address’s Keccak-256 hash is ≥ 8. That pattern is the checksum; digits (0–9) are unaffected.
Do you ever handle private keys?
Never. This works only with public addresses, entirely in your browser. Do not paste a private key or seed phrase into this or any online tool.