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EVM Transaction Calldata Decoder

Inspect raw Ethereum and EVM transaction calldata by separating the 4-byte function selector and 32-byte ABI parameter words directly in your browser.

How to Use

1

Paste your raw 0x-prefixed or plain hex transaction calldata into the input field.

2

Inspect the extracted 4-byte selector and total calldata byte length.

3

Browse each 32-byte parameter word with decimal and hexadecimal offsets.

4

Enter an expected function signature to test whether the selector matches.

5

Optionally expand Custom ABI Types to decode parameters into high-level values.

6

Copy individual words or export the entire decoded structure as structured JSON.

Why Use EVM Transaction Calldata Decoder?

32-Byte Word Offsets

Exposes exact memory offsets (0x04, 0x24, 0x44...) matching EVM CALLDATALOAD semantics.

Intelligent Type Inference

Automatically detects right-padded 20-byte addresses, BigInt uint256 values, and boolean flags.

Local Signature Matcher

Calculates Keccak-256 signatures client-side to verify function calls without external APIs.

Private Calldata Inspection

Debug unbroadcast or private transactions without leaking contract data or parameters.

About This Tool

The EVM Transaction Calldata Decoder breaks down raw hexadecimal transaction input into its 4-byte function selector and 32-byte ABI parameter words. It inspects offsets, infers common data types (addresses, uint256, int256, booleans, and UTF-8 strings), verifies signatures, and allows decoding with custom ABI type lists without connecting to third-party explorers.

Tags:#EVM calldata decoder#Ethereum calldata decoder#transaction calldata decoder#ABI calldata decoder#calldata decoder#Ethereum calldata parser#function selector decoder#ABI parameter splitter

Frequently Asked Questions

Calldata is the read-only, byte-addressable payload sent along with a transaction to a smart contract. The first 4 bytes identify which function to invoke, and the remaining bytes represent ABI-encoded arguments padded to 32-byte words.

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