Keccak-256 Hash Generator
Compute the Keccak-256 hash of text or hex, or the 4-byte function selector for a Solidity signature. Runs entirely in your browser.
🔒 Computed locally in your browser, nothing is sent anywhere.
Building on-chain? A hashing helper is only useful if the contract behind it is safe. Run your Solidity through our free smart contract vulnerability scanner or estimate an audit.
Keccak-256 in Ethereum
Keccak-256 is the hash function at the heart of Ethereum, it derives function selectors, event topics, storage slots, and the hashes signed in EIP-712. It is not the same as the NIST SHA3-256 standard, even though both come from the Keccak family; Solidity's keccak256() is what this tool reproduces.
A common use is deriving a function selector: the first four bytes of the Keccak-256 of a canonical signature such as transfer(address,uint256). Those four bytes are what a transaction's calldata starts with to target a function.
Frequently asked questions
Other free tools
A growing kit of free utilities for builders. No sign-up required.
Smart Contract Vulnerability Scanner
Paste your Solidity code and get an instant heuristic scan for the OWASP Smart Contract Top 10 vulnerabilities.
Smart Contract Audit Cost Estimator
Estimate what a professional smart contract audit will cost based on your codebase size and complexity.
Gwei / ETH / USD Gas Fee Converter
Convert between Gwei, ETH and USD to understand transaction and deployment gas costs.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates, handy for block times and vesting schedules.
Wallet Address Validator
Check whether an Ethereum address is well-formed and EIP-55 checksum valid.
Meta Tag Generator
Generate SEO title, description, Open Graph and Twitter tags with a live Google search-result preview.
Schema Markup (JSON-LD) Generator
Generate FAQ, Article and Breadcrumb JSON-LD structured data to paste into your pages.
Robots.txt Generator
Build a valid robots.txt with crawl rules and sitemap directives.
Building on-chain? We handle the hard parts.
From smart contract architecture to audited deployment, our team ships secure Solidity and Rust.