Crypto Dictionary
Mempool
Definition
A holding area for transactions that have been broadcast to the network but have not yet been included in a block.
Deep Dive
The mempool, short for "memory pool," is a temporary holding area for unconfirmed transactions that have been broadcast to a blockchain network but have not yet been included in a block. When a user initiates a transaction, it is first propagated across the network and lands in the mempools of various nodes. These nodes then hold the transaction, awaiting selection by a miner (in Proof-of-Work) or validator (in Proof-of-Stake) to be added to the next block.
Examples & Use Cases
- 1Bitcoin's mempool during periods of high network congestion, where fees surge
- 2Ethereum's mempool (before PoS) where gas prices determined transaction priority
- 3Solana's mempool, which is processed at an extremely high rate due to its architecture.
Related Terms
Transaction FeesBlockMinerCongestion