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MetaMask Smart Transactions vs Flashbots Protect

How MetaMask Smart Transactions and Flashbots Protect differ on type, protection, rebates and what they’re built for.

MetaMask Smart TransactionsFlashbots Protect
TypeWallet featurePrivate RPC
How it worksSubmits your tx to a private “virtual mempool” and auctions it to trusted builders who are financially penalized if they don’t execute at the quoted price. It stays private until confirmed.Sends your transaction privately to the Flashbots block-building auction. MEV-Share selectively shares hints so searchers can bid to back-run it, sharing the profit with you.
Protects againstFrontrunning + failed transactions (99.9% success rate)Frontrunning, sandwiching & failed-tx reverts
RebatesNo direct rebate — back-run value funds the free service90% of back-run MEV + gas-fee refunds
ChainsEthereum, Linea, Base, Arbitrum, BNB ChainEthereum
SetupToggle on in MetaMask settingsAdd RPC rpc.flashbots.net to your wallet
Best forMetaMask users who want zero setupThe conservative, battle-tested default

MetaMask Smart Transactions

  • Zero setup — built into MetaMask
  • 99.9% tx success rate + pre-simulation
  • Multichain (ETH + 4 chains)
  • Only inside MetaMask
  • No direct rebate to you

Flashbots Protect

  • Most battle-tested private RPC
  • MEV-Share back-run rebates (90%) + gas refunds
  • Permissionless — no API key
  • Ethereum mainnet only
  • Back-run-only sharing today

Bottom line

Pick MetaMask Smart Transactions for metamask users who want zero setup; pick Flashbots Protect for the conservative, battle-tested default.