Ethereum Address Validator
Validate Ethereum addresses with EIP-55 checksum verification, detect address format, and suggest correct checksummed address.
Address Validator
Enter an Ethereum address (0x + 40 hex characters) to validate with EIP-55 checksum verification.
Checksum (EIP-55)
-
Format
-
Length
-
- Enter an Ethereum address — Type or paste an Ethereum address (starts with 0x followed by 40 hex characters).
- Automatic validation — The address is validated in real-time. The tool checks format, hex characters, and EIP-55 checksum for mixed-case addresses.
- View address details — See the checksum status, address format type, and character length.
- Try examples — Click the Example button to test with valid Ethereum addresses.
All validation is performed 100% client-side in your browser. No address data is sent to any server.
What Is EIP-55?
EIP-55 (Ethereum Improvement Proposal 55) defines a method for adding checksum information to Ethereum addresses by using mixed-case characters. Since Ethereum addresses are case-insensitive hex strings, EIP-55 encodes a checksum in the capitalization of the letters (a-f) to help detect typing errors.
The checksum works by taking the Keccak-256 hash of the lowercase address (without 0x prefix). If the nth hex digit of the hash is 8 or higher (bit 3 set), the corresponding character in the address is capitalized. This creates a human-readable checksum that is backward-compatible with all existing Ethereum software.
Addresses in all-lowercase or all-uppercase are still technically valid, but they lack the error-detection benefits of the EIP-55 checksum. Most Ethereum wallets now display addresses in EIP-55 mixed-case format.
Ethereum Address Format
| Property | Value |
|---|---|
| Prefix | 0x |
| Total Length | 42 characters (0x + 40 hex) |
| Character Set | 0-9, a-f, A-F |
| Checksum Standard | EIP-55 (Keccak-256 based) |
| Case Sensitivity | Case-insensitive, but mixed-case has checksum |
What is an Ethereum address?
An Ethereum address is a 42-character hex string starting with 0x. It represents the last 20 bytes of the Keccak-256 hash of the public key, with EIP-55 optional mixed-case checksum encoding.
What is EIP-55 checksum?
EIP-55 adds error-detection to Ethereum addresses by capitalizing certain letters based on the Keccak-256 hash of the address. This helps detect typing errors and prevents sending funds to incorrect addresses.
Are lowercase/uppercase addresses valid?
Yes. All-lowercase and all-uppercase Ethereum addresses are technically valid, but they do not carry the EIP-55 checksum. It is recommended to use the mixed-case checksummed format for safety.
Does a valid address mean the address has ETH?
No. A valid address only confirms the address is correctly formatted with a valid checksum. It does not indicate ownership, activity, or balance. Use a blockchain explorer to check balances.
What is the difference between EIP-55 and Base58Check?
Bitcoin uses Base58Check which adds explicit checksum bytes to the address. Ethereum uses EIP-55 which encodes the checksum in the letter casing of existing hex characters, making it backward-compatible with systems that ignore case.