Mempool

The mempool is the waiting room for unconfirmed transactions: the pool of pending transactions nodes have received but not yet put in a block. Miners or va

The mempool is the waiting room for unconfirmed transactions: the pool of pending transactions nodes have received but not yet put in a block. Miners or validators pick which to include next, typically favoring the ones paying the highest fees.

Why it matters

When you submit a transaction, it first “sits in the mempool.” Slow networks + high demand = long mempool queues and higher fees. It’s also where sandwich bots and MEV exploits happen — watching the mempool to front-run large trades — a real decentralization concern.

Related terms

transaction · mining ·
gas

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