Ethereum (EIP-55) Address Validator
Private by design — runs entirely in your browser
Check whether an Ethereum address is well-formed, calculate its EIP-55 mixed-case checksum, and surface a clear error when a typo flips a hex character.
What is the EIP-55 checksum
A way to encode validation into the address itself by mixing letter case: the keccak256 of the lowercase form picks which letters become uppercase. A wallet sending to a mistyped address can spot the typo.
Is a lowercase address still valid
Yes. EIP-55 makes the checksum verifiable, but lower-case-only and upper-case-only addresses are accepted by every wallet and node.
What does the tool detect
Wrong length, non-hex characters and EIP-55 case mismatches. We display the corrected checksum form so you can paste it back instead of the broken one.
Frequently Asked Questions
- What is the EIP-55 checksum?
- A way to encode validation into the address itself by mixing letter case: the keccak256 of the lowercase form picks which letters become uppercase. A wallet sending to a mistyped address can spot the typo.
- Is a lowercase address still valid?
- Yes. EIP-55 makes the checksum verifiable, but lower-case-only and upper-case-only addresses are accepted by every wallet and node.
- What does the tool detect?
- Wrong length, non-hex characters and EIP-55 case mismatches. We display the corrected checksum form so you can paste it back instead of the broken one.
- Does the address leave the browser?
- No. The check is a tiny piece of JavaScript on this page. We do not log addresses.