Address Checksum (EIP-55)

Validate and convert Ethereum addresses to EIP-55 checksum format so wallet and contract addresses are easier to verify before you store, share, or use them.

Address Checksum (EIP-55)

Validate and convert Ethereum addresses to EIP-55 checksum format so wallet and contract addresses are easier to verify before you store, share, or use them.

Validate Ethereum addresses with EIP-55 checksum casing

Use the Address Checksum tool to normalize wallet and contract addresses, confirm mixed-case checksum formatting, and reduce address-entry mistakes in analytics, allowlists, support workflows, and smart contract operations.

Validate addresses

Check whether a wallet or contract address is valid and uses the expected EIP-55 checksum casing.

Convert lowercase input

Turn a lowercase 0x address into the mixed-case checksum format used across Ethereum tooling.

Reduce address errors

Catch address formatting issues before adding users to allowlists, dashboards, exports, or support records.

How to use the address checksum tool

Paste an Ethereum or EVM address to validate its format and convert it to EIP-55 checksum casing. A checksum address uses capitalization derived from the address hash, which gives wallets, explorers, and developer tools a lightweight way to catch common copy-paste or manual entry errors without changing the underlying 20-byte address.

1. Paste an Ethereum address

Start with any 0x wallet address or contract address from a block explorer, CSV export, wallet connection, CRM, support ticket, or analytics event. The tool can validate lowercase addresses and existing mixed-case checksum addresses.

2. Generate the EIP-55 checksum

The checksum algorithm hashes the lowercase address and uses that hash to decide which hexadecimal letters should be uppercase. The result is the canonical mixed-case EIP-55 representation of the same address.

3. Compare the original and checksummed address

If the original mixed-case address does not match the computed checksum, the address may contain a typo or incorrect casing. Use the checksummed output when storing addresses, reviewing user input, or preparing allowlists.

4. Use checksummed addresses in your workflow

Checksummed addresses help keep wallet analytics, contract management, CSV uploads, identity resolution, and support workflows consistent across Ethereum and EVM-compatible chains.

Address checksum FAQs

Answers to common questions about EIP-55 checksum addresses, validation, and Ethereum address formatting.

What is an EIP-55 checksum address?

Does checksumming change the wallet address?

Why do Ethereum addresses use mixed-case checksums?

Can I checksum a lowercase address?

Which chains use EIP-55 address formatting?

How does address checksum validation help analytics teams?

What is Formo?

Address checksum FAQs

Answers to common questions about EIP-55 checksum addresses, validation, and Ethereum address formatting.

What is an EIP-55 checksum address?

Does checksumming change the wallet address?

Why do Ethereum addresses use mixed-case checksums?

Can I checksum a lowercase address?

Which chains use EIP-55 address formatting?

How does address checksum validation help analytics teams?

What is Formo?

Address checksum FAQs

Answers to common questions about EIP-55 checksum addresses, validation, and Ethereum address formatting.

What is an EIP-55 checksum address?

Does checksumming change the wallet address?

Why do Ethereum addresses use mixed-case checksums?

Can I checksum a lowercase address?

Which chains use EIP-55 address formatting?

How does address checksum validation help analytics teams?

What is Formo?

Formo makes analytics simple

Measure what matters and drive growth onchain.

Formo makes analytics simple

Measure what matters and drive growth onchain.

Formo makes analytics simple

Measure what matters and drive growth onchain.