Before your MetaMask swap, add the Flashbots Protect RPC as a custom Ethereum mainnet network, switch to it, send, then check the hash on the Protect status page. The Flashbots route keeps the pending swap out of the public mempool because the Flashbots Protect RPC receives it only while that network is selected.
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If your wallet cannot add a custom RPC, this setup will not route the swap privately; use a wallet or swap flow that supports protected submission.
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If you have no ETH for gas, or set the priority fee to zero, the transaction cannot proceed through this route.
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If you already sent the swap through a public RPC, switching networks afterward cannot make that submission private.
How Do You Add Flashbots Protect to MetaMask?
Add a custom network that uses the Protect RPC for Ethereum mainnet. In the Protect configuration flow, you can choose the Fast preset or adjust builder and refund settings, then copy the RPC URL it generates. Sending to more builders can improve the chance of inclusion, while the refund setting affects how much of an eligible MEV refund you keep. For one swap, choose those settings before copying the URL; they are part of the route you are about to use.
In MetaMask, open the network menu, choose Add network, then Add a network manually. Enter a recognizable network name, paste the copied URL into New RPC URL, set Chain ID to 1 and Currency Symbol to ETH, and save. Select the new network. Its name helps you spot the active RPC; the name itself provides no protection.
Your address, tokens and ETH balance should look the same as on your usual Ethereum mainnet entry. Both entries use chain ID 1 and the same account. The RPC is the part that changes: it is the server MetaMask contacts to submit the signed transaction. Seeing familiar balances therefore confirms you are still looking at mainnet, but does not confirm which route a future swap will take. Read the selected network name before signing.
What Should You Confirm Before Sending the Swap?
Confirm that MetaMask is still on the Protect network when the swap asks you to sign. A swap site may show the right tokens and quote while the wallet is connected through your default public RPC. The wallet sends through its selected RPC, so the network menu is the decisive setting for this transaction.
Review the swap amount, minimum received and slippage tolerance in the trade confirmation. Slippage is the maximum price movement you permit between the quote and execution. A very wide tolerance can leave you accepting a much worse price even when the transaction stays private; an unusually tight one can prevent the swap from executing as the market moves. Choose it for the token’s liquidity and the price movement you are willing to accept, rather than treating private routing as a price guarantee.
Leave enough ETH to cover gas and use a nonzero priority fee. The priority fee is the part of the gas payment that helps make inclusion worthwhile; Protect rejects a transaction with a zero priority fee. After signing, copy the transaction hash from MetaMask. That hash identifies this particular swap for the status lookup, including while it remains invisible to a public block explorer.
Private submission limits the public mempool exposure that enables a typical sandwich attack: a bot sees a pending swap, trades ahead of it, then trades behind it. It does not make the swap secret forever. Once included, its details are on Ethereum, and the builders that receive it are part of the trust decision you made in the configuration flow.
How Can You Tell the Swap Used Protect?
Enter the copied hash on the Flashbots Protect transaction status page. A recognized pending transaction shows that the private route received it; an included status, together with a block containing the same hash, completes the check. A block explorer is useful for confirming inclusion, but a confirmed transaction there alone cannot tell you which RPC originally received it.
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Pending on the Protect page, absent from a public explorer: the transaction is waiting privately. Its absence from the explorer does not mean MetaMask lost it.
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Included on the Protect page, with the same hash in an Ethereum block: the protected submission was included. Confirm the swap’s actual token amounts in the transaction receipt.
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Visible as pending in a public explorer: the transaction has reached the public mempool, so do not assume it retained private routing.
What If the Private Transaction Stays Pending?
A pending status means the swap has not landed in a block yet. Builder selection, fees and whether the swap can execute at your chosen slippage can all affect inclusion. Keep the transaction hash and watch its status before deciding what to do next. Repeatedly submitting the same trade without resolving the pending transaction can also leave you unsure which transaction will use the account’s next nonce.
Keep MetaMask on the Protect RPC until the transaction confirms. Switching RPCs while it is pending can cause MetaMask to resend it publicly. Likewise, a speed-up or cancel sent through a public RPC exposes the replacement transaction and can reveal the trade attempt. If you need to replace a stuck transaction, first establish how your wallet will route that replacement; the original network choice does not automatically protect a later submission.
For this swap, the result is established when the Protect status page shows inclusion and the same hash appears in a block. The selected RPC determines where MetaMask sends the transaction, and the status page confirms what happened after submission. That combination lets you verify a protected route rather than infer one from a normal-looking wallet balance or a block explorer result.