CryptoCheck.tools
Free crypto utility tools — Wei/Gwei/ETH converter, checksum address validator, Keccak256 hash generator.
Wei / Gwei / ETH Converter
Convert between Wei, Gwei, and Ether denominations
Checksum Address Validator
Validate and checksum Ethereum addresses (EIP-55)
Keccak256 Hash Generator
Generate Keccak-256 hashes from text or hex input
Premium Resources
Crypto Developer Cheat Sheet
Solidity patterns, gas optimization tips, EVM reference. PDF download.