Calldata Decoder
Named arguments from calldata — or the raw 32-byte words without an ABI.
Runs offline
Paste calldata. A signature or ABI names the arguments; without one you still get the selector and raw words.
About calldata decoder
Calldata is the payload of a contract call: four bytes identifying the function, then the arguments packed into thirty-two-byte words. Give it a signature or an ABI and you get named arguments back. Give it nothing and you still get the selector and the raw words, annotated where a word looks like an address or a plausible amount — often enough to work out what a transaction does before you sign it.
Common questions
How do I decode Ethereum transaction input data?
Paste the hex calldata. When a matching signature is known, this names the function and arguments; when it is not, it still splits the payload into the four-byte selector and 32-byte words so you can read the structure without an ABI.
What if the ABI is unknown?
The decoder still shows the raw words. A missing ABI does not mean the call is safe or unsafe — only that names are missing. Pair this with a simulator or signature decoder when the question is what the call would actually move.
Does decoding calldata mean the transaction is safe?
No. A clear decode can still grant an unlimited approval, call a hostile contract, or move funds somewhere you did not intend. Decoding explains the shape of the call; it is not clearance to sign or send it.