What Is “Fee Sniping” and How Does It Relate to Transaction Prioritization?

Fee sniping is a malicious or opportunistic mining practice where a miner attempts to steal the transaction fees of a block that has already been found by another miner but not yet fully propagated and confirmed. It involves the second miner quickly building a new block on top of the first one, but replacing the first block's transactions with a higher-fee set from the mempool.

This practice is largely mitigated by modern consensus protocols and orphan block mechanisms.

How Does the “Orphan Block” Mechanism Discourage Fee Sniping?
How Does EIP-1559 Change the Way Transaction Fees and Prioritization Work on Ethereum?
What Is the Concept of “Selfish Mining” and How Does It Differ from Fee Sniping?
How Does the Block Propagation Time Influence the Success of Fee Sniping?
How Do Transaction Size and Fee Relate to the ‘Fee Rate’?
What Is the “Longest Chain Rule” and How Does It Relate to Block Confirmation?
How Does a Transaction with a Zero Fee Get Confirmed in a Low-Traffic Blockchain?
How Can a User Estimate the Optimal Fee for Their Transaction?

Glossar