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Flashbots Protect vs MetaMask Smart Transactions

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

Flashbots ProtectMetaMask Smart Transactions
TypePrivate RPCWallet feature
How it worksSends 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.Submits 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.
Protects againstFrontrunning, sandwiching & failed-tx revertsFrontrunning + failed transactions (99.9% success rate)
Rebates90% of back-run MEV + gas-fee refundsNo direct rebate — back-run value funds the free service
ChainsEthereumEthereum, Linea, Base, Arbitrum, BNB Chain
SetupAdd RPC rpc.flashbots.net to your walletToggle on in MetaMask settings
Best forThe conservative, battle-tested defaultMetaMask users who want zero setup

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

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

Bottom line

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