What Are Blockchain Confirmations and How They Work
What Are Blockchain Confirmation Times?
Public blockchains all use something called blockchain confirmations. When a transaction is first sent to the blockchain it starts with zero confirmations. The number then increments as the information is added to the first block confirmed, given a permanent location, and then more blocks are added.
Blockchain confirmations are of vital importance since they verify and legitimize information that will then become unchanged once recorded on the ledger. If a transaction is considered fake, the blockchain will reject it: zero blockchain confirmations translates to zero transactions.
Crypto exchanges require on average a minimum of three confirmations until a transaction is accepted. However, the number of blockchain confirmations required depends on how large the transaction is. This is because if there are more confirmations, it will be harder for the transaction to be reversed.
Each blockchain has a different amount of blockchain confirmations required to verify a transaction.
Bitcoin’s blockchain generates a new block through mining about every 10 minutes. This block then verifies and records new transactions and links them to the Bitcoin blockchain. This means that a transaction remains unconfirmed until the miners generate a new block. So, if you’re sending or receiving Bitcoin, you must wait until it appears that the transaction has been confirmed.
One confirmation usually requires up to 10 minutes. But, since one confirmation is not enough to prove the transaction is valid, users have to wait for each new block to be generated and verify the information. Depending on the amount transacted, this may take anywhere from 30 to 600 minutes.
Some Bitcoin services only require the first confirmation and therefore they are almost instant, however, the majority ask for a minimum of three to six Bitcoin blockchain confirmations before accepting the transaction.
What Is the Bitcoin Mempool?
The Bitcoin Mempool is where unconfirmed Bitcoin transactions on the Bitcoin network are sent. When a transaction is broadcasted to the blockchain, it is not confirmed immediately but is directed to the mempool of transactions, which are considered in-motion.
All nodes on the Bitcoin network communicate with the mempool, as well as the miners who gather transactions from the mempool into a block. The miner who finds the first solution for the mathematical equation and adds the block to the blockchain is the first to confirm the block. When the block is confirmed, the miner will receive the reward of 12.5 BTC.
The process seems very direct, however, some transactions are taken out of the mempool faster than others. This happens because miners also get a bonus percentage of the transaction fees which incur in the mining process.
Miners take out from the pool the transactions that have higher fees first, so they can earn a higher bonus. This is also why not paying transaction fees can lead to longer confirmation times. This also applies when more people join the Bitcoin network, thus leading to a traffic jam and long waiting times.
How to Check Bitcoin Confirmations
After you have completed your transaction, you should have an option in your wallet which allows you to view the transaction on a block explorer or display the transaction ID.
A transaction ID is a long string of letters and numbers that are mixed up randomly. To see the number of confirmations for a transaction, paste the ID into a block explorer.
What Is the Average Bitcoin Confirmation Time?
The probability of having your transaction confirmed within 10 minutes can be increased to 60% if you pay a high enough fee.
If your transaction goes unconfirmed for hours, do not get impatient and continue waiting. If more than 72 hours have passed and there is still no confirmation, you can re-send the transaction.
How to Speed Up Blockchain Confirmation Times
As we mentioned above, if you pay a higher fee, your transaction will have a higher chance of being confirmed faster. However, if your transaction is still unconfirmed, then the recommended wait time is 72 hours before you can re-send it.
However, in order to avoid paying fees, you can verify the number of unconfirmed transactions there are at a specific moment and calculate how long it will take.
Ethereum Blockchain Confirmations
Regarding Ethereum blockchain confirmations, the number of confirmation required has not been fixed. The whitepaper states that 7 confirmations should be enough to confirm the transaction (which would require 2 minutes).
However, Ethereum miners have to verify the parameters of the last 250 blocks. So, if you want to make sure everything will function accordingly, you should wait for 250 confirmations. While the number might make you think the process will take forever, it will only be about an hour or so.
Etherscan and Ether Gas
Ethereum doesn’t have a mempool instead, it stores its pending transactions in a transaction pool. All the transactions submitted that haven’t yet been assigned to a block are sent into the pool.
There are various ways in which you can speed up your transaction and determine the best gas price when sending your Ethereum transaction. You can check to see overall gas usage with ETH Gas Station, and you can view how many transactions are in pending by using Etherscan.
Blockchain confirmations are important for ensuring the security and validity of transactions. The easiest way of having your transaction confirmed faster is by paying a higher fee.