Mempool

The Mempool (short for memory pool) is a temporary holding area where unconfirmed blockchain transactions wait before being included in a block. Each network node maintains its own mempool, and miners or validators choose which transactions to process.

How the Mempool Works

A user submits a transaction

The transaction propagates across nodes

Each node adds it to its mempool

Miners/validators select transactions (usually highest fees first)

Once included in a block, it is removed from the mempool

The mempool acts as a buffer between users and block inclusion.

What Affects Mempool Congestion

High network activity

NFT mints or popular token launches

Market volatility causing many swaps

Low gas prices set by users

Spam or malicious transactions

During congestion, gas fees typically rise.

Why the Mempool Matters

Determines gas fees

Impacts transaction speed

Reflects real-time network demand

Enables MEV strategies by exposing pending transactions

Summary

The mempool is the waiting area for unconfirmed transactions before they are added to a block. It influences fees, speed, and miner/validator behavior.