Why hex shows up everywhere in Ethereum
Addresses, transaction hashes, calldata, storage slots — Ethereum represents almost everything as raw bytes, and hex is the standard way to write bytes as text. A block explorer showing you0x48656c6c6f is showing you 5 bytes; whether those bytes are meant to be read as a number, a string, or something else entirely depends on context the hex itself doesn’t carry.
When each field is useful
Decimal is what you want when a hex value is actually a plain number — a token ID, a block number, an amount before you know its decimals. Text is for the cases where on-chain bytes are meant to be read as a string, like some NFT metadata fields or ENS-adjacent data. Not every hex string is valid UTF-8 text, and this tool tells you plainly when that’s the case rather than showing mangled output.
How this tool works
Every conversion happens with native BigInt and the browser’s built-in text encoder/decoder — no library, no rounding, no size limit beyond what your browser can hold in memory. Nothing you type is sent anywhere.