How do you read a transaction on a block explorer?

Start with the hash

A transaction hash is a unique code made for every transaction. You use it to find the transaction and follow its status.² Etherscan says it is also called a transaction ID.² On Ethereum it is a 66-character string that starts with "0x".³

Paste the full hash into the explorer's search box. Nothing else is needed.⁵

The fields, top to bottom

Explorers lay pages out in their own ways, but the main fields are the same.^1,3

Status: pending, success or failed

Pending means the transaction is waiting to be put in a block.⁸ Etherscan says that at very busy times this can take hours or even days.⁸ A pending transaction can also be dropped. If it is never broadcast again, it is as if it had never happened.⁹

Success and failed come from the transaction's receipt. Ethereum nodes give no receipt for a pending transaction. Once it is in a block, the receipt holds a status: 1 for success, 0 for failure.¹⁰

A failed transaction moved nothing, but still cost a fee. Etherscan says the funds stay in the sender's wallet and the gas fee is still deducted.¹¹ Module 5 explains why.¹¹

Block and confirmations

Blocks are numbered in order, starting from block 0.² The block number tells you where the transaction sits in the chain's history.²

Next to it, explorers show a count of block confirmations, which goes up by one with each new block. The more confirmations, the more secure the transaction is considered to be.^12,2

On Ethereum, ethereum.org says the block holding your transaction later becomes "justified" and then "finalized", which makes it far more certain that it will never change.⁶ Module 2 explains finality.⁶

Many exchanges wait for a set number of confirmations before they credit a deposit, and each sets its own number.^13,12

The fee

For an ordinary Ethereum transaction, the fee on an explorer page is gas used × gas price.^2,1 "Gas used" is the exact units of gas the transaction used, not the limit the sender set.²

The gas price here is the price actually paid per unit. Ethereum's standard JSON-RPC interface calls it the effective gas price: the base fee plus the tip, per unit of gas.¹⁰ Module 5 explains gas, the base fee and the tip. This lesson just reads them off the page.¹⁰

The sender pays the fee, on top of anything it sends. In ethereum.org's example, Bob sends 1 ETH and his account goes down by 1.0042 ETH: 1 ETH for Alice and 0.0042 ETH in fees.⁶

A real example

Here is a real token transfer from 6 December 2021, as Etherscan showed it when we read it in October 2026.⁴

Check it yourself: 34,795 × 109.275194209 = 3,802,230.382502155 gwei, which is 0.003802230382502155 ETH. That is exactly the fee shown.⁴ The value is 0 ETH because this transaction moved tokens, not ETH. Lesson 3 shows where they appear.^4,3

Input data

When a transaction calls a contract, its input data says which function to run.⁷ The first four bytes are the Method ID, also called the function selector.^6,14 In the example above it is 0xa9059cbb, which the token's published code names as transfer(address recipient, uint256 amount).^4,6

Etherscan can only name the function for sure when the contract's code has been published and checked. For other contracts, Etherscan guesses by matching known functions, and says the result may not be 100% reliable.¹⁴ Different functions can even share a Method ID, and Etherscan warns that tricksters may use this to fool you.¹⁴

Input data can also carry a plain message instead of a function call.⁷