Ethereum Address Checksum Tool
Validate an Ethereum address and convert it to its EIP-55 checksummed form. Mixed-case checksums catch typos before you send funds.
0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAedWhy address checksums matter
Ethereum addresses have no built-in error detection: any 40-character hex string is a syntactically valid address. EIP-55 fixes this by using the capitalization of the letters a to f to carry a Keccak-256 checksum. The address still looks the same and works the same, but software can now flag a single mistyped character.
Paste any address above. If it is all one case, you get its checksummed form. If it is mixed case, the tool also tells you whether the existing checksum is valid.
Frequently asked questions
What is an EIP-55 checksum address?
EIP-55 encodes a checksum into the capitalization of an address's hex letters. Wallets can then detect a mistyped address without changing its length or adding characters.
How is the checksum computed?
Take the lowercase address, hash it with Keccak-256, and for each hex letter uppercase it when the matching hash nibble is 8 or greater. The result is the checksummed address.
My address failed validation, what does that mean?
A mixed-case address that does not match its checksum usually means a typo. Double-check the characters before sending funds, since the checksum exists to catch exactly this.
Is an all-lowercase address valid?
Yes, an all-lowercase or all-uppercase address is accepted everywhere because it carries no checksum to verify. Convert it here to the safer checksummed form.
Building on Ethereum?
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