MEV protection in MetaMask

MetaMask offers MEV (Maximal Extractable Value) protection to secure your transactions and ensure fair market value. MEV protection safeguards eligible transactions from harmful MEV strategies like front-running and sandwich attacks, providing a safe environment for transacting in MetaMask on supported chains.

What is MEV protection?

MEV refers to the maximum amount of value extracted in block production via the reordering, inclusion, or exclusion of transactions from a block, beyond the typical network fees. MEV extraction often comes at a cost to users — malicious strategies such as sandwiching and front-running can create worse transaction prices or even cause users to lose their transactions under certain circumstances.

Transactions are at risk of these practices when they enter the public mempool, where they wait to be included in a block. By scanning the public mempool, harmful actors can insert their own transactions around yours to profit at your expense.

To help protect you from harmful MEV strategies, MetaMask privately auctions eligible transactions rather than sending them to the public mempool. Trusted network participants bid for the right to include these routed transactions in a block, thus avoiding malicious MEV practices.