Smart Contract Decoder

Paste transaction input data and decode the function using ABI.

Provide ABI JSON and calldata to decode the matched function name, signature, and argument values locally in the browser.

{{ status.label }}

{{ decodedSignature || 'No decoded function yet' }}

{{ status.message }}

{{ abiLength }} ABI characters
{{ inputLength }} input characters

Decoded function

{{ decodedFunction || 'Decode the transaction input to see the matched function name.' }}

Decoded parameters

{{ decodedArgsText || 'Decoded arguments will appear here as formatted JSON.' }}

Typical uses

Wallet debugging

Inspect calldata from a wallet or block explorer and confirm which function was called.

Protocol analysis

Match selectors to ABI functions when reviewing contract interactions.

Support work

Decode user-submitted transaction input without connecting to a node.

Smart contract decoder FAQ

What do I need to decode a transaction input?

You need the contract ABI and the transaction input data. The decoder matches the function selector in the input data against the ABI.

Does the decoder call a blockchain RPC?

No. Decoding runs locally in the browser using only the ABI and input data you paste.

Can it decode constructor data or logs?

This page is focused on transaction input data for function calls. It does not decode event logs or deployment bytecode here.