blockchain.info – What is the longest unconfirmed transaction?

Transactions may remain unconfirmed indefinitely.

The order in which transactions are confirmed is determined by miners, who are typically incentivized to include only transactions with the highest commission rates to maximize profits.

Even transactions with low commission rates may eventually be confirmed once the mempool is cleared. However, there is no guarantee about this. If the mempool is full for a long period of time, many nodes may delete the lowest fee transactions from the mempool to free up memory resources (which they might otherwise publish, causing a DoS attack on the network). infinite low fee trading).

Ultimately, once you post a transaction on the network, you cannot be sure if or when it will be confirmed until it is confirmed. Paying a higher fee increases your chances of getting a quick confirmation. On the other hand, low-fee transactions may never be confirmed. This is because eventually all nodes may ‘forget’ this.

If you have waited a long time for a transaction to be confirmed, you can post a new transaction using the same output but with a higher fee. You may need to force your wallet to forget previous transactions so you can create new ones, e.g. bitcoin-cli abandontransaction "txid" If you use Bitcoin Core), not all wallets include this feature.