calldata decoder

paste tx input data, get the function and every argument, decoded.

calldatathe tx input data, starting 0x
try
abi or signature (optional)only needed when the function is unknown

paste calldata above, or tap an example. it decodes as you paste.

about this tool

Decode Ethereum / EVM transaction calldata. The function is detected automatically from its selector, or paste a signature or ABI. Arrays, tuples and bytes included.

good to know

how is calldata laid out?

4-byte function selector, then the arguments abi-encoded in 32-byte words. static values sit inline; dynamic ones (bytes, string, arrays) are an offset pointing further down where the length and data live.

where do i find a transaction's calldata?

the "input data" field on a block explorer, tx.data in viem / ethers, or cast tx <hash> input.

it says unknown selector. now what?

the function was never registered in the public signature databases. paste its signature or the contract abi (from the verified source or your build output) and it decodes locally.