Raw Ethereum Transaction Decoder

Every signed Ethereum transaction is a chain of RLP-encoded bytes — a recursive length-prefix serialisation format that packs nonce, gas, value, recipient, calldata, and ECDSA signature into a single hex string. Explorers decode this for you after broadcast, but sometimes you need to inspect a transaction before it hits the mempool: verifying a hardware wallet's signing output, auditing a relay service, or debugging a raw transaction from a test suite.

Paste any 0x-prefixed hex string and every field appears immediately. The decoder supports all three transaction envelopes: legacy type-0, EIP-2930 type-1 (access lists), and EIP-1559 type-2 (base fee + priority fee). Nothing is sent anywhere; the RLP parser runs entirely in your browser.

Load Sample inserts a legacy type-0 ETH transfer of 0.05 ETH to0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045with a gas limit of 21 000 and a 20 Gwei gas price, zero calldata — the simplest well-formed transaction the decoder can show.

What Each Field Means

• Nonce: the sender's transaction count at the time of signing. A nonce mismatch ("nonce too low") is the most common reason a replay of an old raw transaction is rejected.
• Gas Limit: maximum gas units the sender is willing to spend. 21 000 is the exact cost of a plain ETH transfer with no calldata.
• Gas Price / Max Fee / Priority Fee: shown in wei, Gwei, and ETH so you can compare against current network conditions at a glance.
• To: the recipient address, or (contract creation) when the field is absent, meaning the transaction deploys a new contract.
• Value: native ETH transferred, converted to Gwei and ETH alongside the raw wei figure.
• Data: the calldata payload. When the first four bytes match a known ABI selector (such as 0xa9059cbb mapping to transfer(address,uint256)), the decoder labels it inline. Use the ABI Encoder tool to decode the full parameter list.
• Access List (type-1 and type-2 only): the pre-declared storage slots that earn a gas discount under EIP-2930. Each entry shows the warm address and any storage keys.
• v / r / s: the three ECDSA signature components. For type-0 with EIP-155, v encodes the chain ID asv = chainId × 2 + 35 (or 36). For typed transactions, v is just the recovery bit (0 or 1).

Worked Example: the EIP-1559 Approve Calldata

Click Load Sample twice to cycle to the EIP-1559 entry: a type-2 transaction on chain 1 (Ethereum Mainnet) calling approve(address,uint256) on the USDC contract (0xa0b86991c6…eb48). The calldata field shows selector 0x095ea7b3 and the inline label confirms the function name. Max fee is 30 Gwei, priority fee is 2 Gwei. The access list is empty for this transaction, so no pre-warmed slots.

Precision Limits and What This Tool Cannot Do

Gas and value fields are decoded as BigInt, so there is no overflow up to 2²⁵⁶ minus 1. The inline function-selector lookup covers 13 common ERC-20 and Uniswap methods; anything outside that set shows raw hex without a label. Use the ABI Encoder tool to decode the calldata fully. The tool does not recover the sender address: that requires an elliptic-curve point multiplication over secp256k1, which is outside the scope of a client-side decoder. Transactions longer than a few kilobytes decode fine; the data field truncates its display to the first 33 bytes with an expand toggle, but the full hex is always copyable.