What is a Block Explorer
It is known that all the blockchain transactions are public. You can even download all the logs from a node and see all the blocks, transactions, and smart contracts by yourself, but a more simple and user-friendly method is called “Block Explorer”. You can enter a block explorer simply by looking it up on the internet. For example, a bitcoin block explorer is available at this link.
Seeing a block explorer for the first time can be intimidating, there are a lot of strange numbers and words. Addresses, blocks, transactions, and miners all sum up to a “difficult to understand” interface, but a very powerful one once you learn to read it.
We will be using an Ethereum block explorer called Etherscan for our examples, but the ideas behind all of this are shared among different block explorers for different blockchains.
In a block explorer, you can see who sent a certain amount of a cryptocurrency to who. Every time this happens, it is saved in a transaction. Every transaction is identified by a “transaction hash”, which is a string of characters that uniquely identifies that transaction.
Here, in this randomly picked transaction, we can see the Transaction Hash that identifies it (First row). The status field shows us if the transaction is Pending (It hasn’t been completed yet), Failed (it couldn’t be done), or Success (It is completed).
The Block field indicates in what block the transaction is registered. Lastly, the Timestamp shows us when the transaction was done.
In the next section of the transaction, we can get details of the amount of the currency that was transferred. For example, with the same transaction we’ve been looking at:
Here we can see from what wallet address to another wallet address the currency was sent. As with the Transaction Hash, every user has a wallet address that identifies them. These addresses have a format, for example, in Ethereum, every address starts with “0x”.
Below that we can see the amount of Ether that was sent, in this case is $208.40, and then, the transaction fee. The transaction fee is a small amount that goes to the miner as a reward for providing its resources.
Lastly, the final details of the transaction are the following:
First, we can see what the Gas Price was in the network. Gas refers to the unit that measures the amount of computational effort required to execute specific operations on the Ethereum network. Every transaction needs some computational resources to be executed, therefore, it has an amount of gas that needs to be paid. Gas Price refers to the price per unit of gas in the transaction.
Gas Limit and Usage refers to the limit of gas that the transaction can use and the amount of gas it has used respectively. Base Fee refers to the network Base Fee at the time of the block, while Max Fee and Max Priority Fee, refer to the max amount a user is willing to pay for their transaction and to give to the miner respectively.
Lastly, Burnt refers to the amount of the currency that was burned in the transaction, and Txn Saving Fees refers to the amount of money that the user saved with the Gas Price.
As we can see, a lot of information is packed within the details of a transaction on a block explorer, but they are completely transparent, that is one of the reasons why blockchain technologies are so secure. For example, contrary to what many people think, money laundering is almost impossible using cryptocurrency, because it is really easy to trace back the origins and the movement of the money while it was on the blockchain.