The Anatomy of a Transaction: how to use Etherscan

Published in

Tangem

6 min readSep 2, 2022

We will use a single transaction as an example to learn how to check transaction details on Etherscan blockchain explorer.

The first and main tab is Overview.

Transaction hash

The first component is the hash of the transaction, which is also its unique identifier, created with an encryption algorithm.

Why do we need it?
To analyze information available by unique identifier.

To give you the most obvious example: if you buy something for crypto, pay for it, the seller asks you to confirm the transfer. You copy the hash and send it to the seller. The seller can check the sender’s and the receiver’s addresses, the amount of crypto, time of transaction and other details on the explorer.

If you received crypto (or you sent it to yourself), compare the hashes to be sure that you received the transfer that was sent.

Status

Transaction status. Check the state of the transaction at least 30 seconds later after sending crypto. There are 4 types of statuses:

Success: the transaction was successfully completed;

Failed: the transaction was not completed, an error occurred, everything was canceled, as if there were no transaction;

Pending: transaction is in progress. It is waiting in the memory pool for a miner to create a block.

Dropped and Replaced: the parameters of the transaction were changed to complete it faster. Later, we will discuss which transaction parameters can be changed.

Why do we need it?
We need it to be sure the transaction was successful or to repeat the transaction if it has failed, or to change the parameters if it has been pending for a long time.

Block

Here you can check the total number of blocks mined in the Ethereum blockchain and the number of blocks containing your transaction records. Those blocks were mined after your transaction.

Why do we need it?
Each new block includes a hash of the previous one, providing multiple, mutually certifying and irreversible backup of information. More blocks in the network and more blocks containing your transaction records mean more reliable protection for your crypto.
Different services require a different number of confirmation blocks to complete a transaction. For example, Binance requires12 confirmation blocks.

Timestamp

The date and the time that the first block with the transaction record was mined. In other words, the moment when the transaction was fixed in the blockchain.

Why do we need it?
It is at least another transaction identifier for you to view the transaction, sender’s address, the period it took and so on. Please, keep in mind the transaction status is not dynamic, the timestamp will not change automatically. Therefore, if you made a transaction a day ago, and the timestamp is still showing 1.5 hours ago, just refresh the page.

Transaction action

The field shows different parameters regarding the structure of the transaction: the amount of sent crypto, service involved, and so on.

Why do we need it?
For advanced analysis of transactions, as well as for checking the state of the network.

Transaction Action field shows us Revoked USDT From Trade On Metamask: Swap Router. Now we know the transaction was not a transfer of crypto, payment, and so on. The user needed to revoke Metamask (exchange service and popular browser wallet) permission to exchange ETH for USDT.

Etherscan shows you which dApps have token approvals to your wallet: click on Token approvals.

Below we see From and To fields: the address that sent the transaction and the address that the transaction is addressed to. But in our example, To contains the smart contract address, a protocol in the USTD blockchain with the transaction details ensuring its completion.

Value

Transaction value: the amount of the sent crypto.

If we transfer 2 ETH, the Value field would contain 2 ETH (the commission would not be displayed). But in our example, for some reason, the Value is 0 ETH. Why is that?

Actually, the answer is clear from Action: as it was not a transfer or payment, sending of crypto coins, or something like this. The transaction was to revoke the dApp’s access to transactions with the tokens in your wallet. It was not, therefore, crypto transfer, the user just paid the network commission.

The commission is charged in any blockchains for any transactions. Commission is the reward for miners validating transactions.

The commission fee is calculated depending on different factors based on transaction parameters. For example, if you want the transaction to be completed as soon as possible, you can pay a high commission. And if it is not urgent, you can pay less.

Transaction Fee shows the amount of commission in ETH and USD for revoking access. The next two fields show gas price and ETH value.

Why do we need it?
For checking the network state and its dynamics, for selecting commission fee for transactions.

Gas limit and use, commission components

The following field will be available after clicking Show More:

Gas limit and gas used by transaction: the first number shows the maximum amount of gas the user was willing to pay for the transaction, the second shows how much of this amount was actually spent (in absolute values and percentages).
Commission options at the time of block generation. Base fee is the basic part of the commission. Gas is spent during the transaction. For basic operations such as transfers, it can reach 21,000 Gwei, but in our example, we see 20,600 Gwei. Max is maximum Gwei the user is ready to pay for the transaction, and Max Priority is the transaction priority fee for the miner who created the block (tips).
Burnt & Txn Savings Fees: Burnt is the amount of gas spent as part of the transaction fee, the Saving Fee is the difference between the fee that the user was ready to pay and the actual amount of fees.

Why do we need it?
For checking the network state and for selecting commission fee. For example, we see that the base fee is lower than 21,000 Gwei, meaning that the network is not busy, and you can pay less fees. And if only 60.7% of gas reserved for the commission was burnt, it also means the network was not busy.

Other

In our example, we see the following fields:

Txn type: 2 (EIP-1559). It means it was a Type 2 EIP-1559 transaction in the London hard fork of the Ethereum. It is a new technology for calculating transaction fees: the gas price is multiplied by the gas spent. These transactions are considered to be Type 2, while Type 0 transactions support the previous algorithm.
Nonce: the count of transactions sent out of the address.

Position: position of this transaction in the Ethereum (do not confuse with the Block showing the number of the block in the blockchain)

Why do we need it?
Reference information for experts

Input data

Additional information about the transaction. In our example we can see the spender address, the address of the smart contract, and value of transferred funds in a 256-bit value. It is 0, as the crypto was not actually sent.