Web3 & blockchain

EVM unit conversion, Keccak-256 hashing and hex utilities for smart contract work, all offline.

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EVM Unit Converter

Convert between wei, gwei and ether with exact BigInt precision. Free, instant and 100% client-side, made for gas math without floating-point errors.

Keccak-256 Hash

Compute Keccak-256 hashes and Solidity function selectors online. Free and 100% client-side; the hash used by Ethereum, computed in your browser.

Hex ↔ String Converter

Convert text to hexadecimal and hex back to readable text, UTF-8 aware. Free, instant and 100% client-side; decode calldata and bytes right in your browser.

Ethereum Transaction Decoder

Decode a raw signed Ethereum transaction and recover the sender address. Free, 100% client-side; RLP parsing and ECDSA recovery run in your browser.

Which tool should I use?

EVM Unit Converter converts between wei, gwei and ether values. Ethereum Transaction Decoder decodes a signed raw transaction to show what it actually does.