A mempool is a digital waiting area for unconfirmed transactions on a blockchain, where they are stored and validated before being added to the blockchain.

Mempool Explained

Imagine a bustling city bus station — this is akin to a mempool in the blockchain universe. A mempool, short for memory pool, serves as a holding area for unconfirmed transactions on a blockchain network. Each node, or computer connected to the network, operates its own mempool, ensuring transactions are in order before they join the blockchain ledger.

How Transactions Enter the Blockchain

  1. Transactions are broadcast to the network and initially land in the mempool.
  2. Nodes validate transactions, checking for accuracy and legitimacy.
  3. Miners or validators select transactions from the mempool when creating a new block.
  4. Once a block is confirmed, the transactions within are considered ‘confirmed’ and leave the mempool.

What Happens to Stalled Transactions?

Not all transactions make it to the blockchain swiftly. Some may linger due to low fees or network congestion. If a transaction remains unconfirmed for an extended period, typically around 48 hours, it may be dropped, returning the funds to the sender’s wallet.

Why Transactions Get Stuck in the Mempool