Go to Fast Swaps
Open your browser and navigate to fastprotocol.io.You will see the Fast Swaps landing page with the swap interface.
Connect Your Wallet
Click the Connect Wallet button in the top-right corner of the page.
A wallet selection modal will appear. Choose your wallet provider:
Your wallet extension will prompt you to approve the connection. Confirm the connection in your wallet.
- MetaMask
- Rabby
- WalletConnect (for mobile wallets or other providers)
Select the Token You Want to Sell
The swap interface has two sections: Sell (top) and Buy (bottom).Click the token selector button in the Sell section. By default, it may show ETH.
A token selector modal opens where you can:
Select the token you want to sell. For this guide, we will use ETH.
- Search by token name or symbol (e.g., “USDC” or “Uniswap”)
- Browse popular tokens in the top carousel (ETH, USDC, USDT, DAI, WBTC)
- Paste a contract address to add any ERC-20 token not in the default list
Select the Token You Want to Buy
Click the token selector button in the Buy section and choose your desired output token. For this guide, we will select USDC.
Enter the Swap Amount
Click the amount field in the Sell section and type the amount you want to swap. For example, enter 
As you type, Fast Swaps automatically:
0.1 to swap 0.1 ETH.- Fetches a real-time quote via a competitive solver auction
- Displays the output amount in the Buy section
- Shows the exchange rate (e.g., “1 ETH = 2,450.32 USDC”)
- Shows price impact — the effect your trade has on the market price
Review Swap Details
Before confirming, review the swap details displayed below the Buy section:
| Detail | What It Means |
|---|---|
| Exchange Rate | How much of the output token you get per unit of input token (e.g., 1 ETH = 2,450 USDC) |
| Price Impact | How much your swap moves the market price. Green is negligible, yellow is moderate, red means you may want to reduce your swap size |
| Minimum Received | The worst-case amount you will receive after slippage tolerance is applied |
Adjust Slippage (Optional)
Click the settings gear icon to open transaction settings. Here you can adjust:- Slippage tolerance — The maximum price movement you are willing to accept. Default is “Auto,” which sets an appropriate value based on the token pair. You can set a custom percentage (e.g., 0.5%, 1%).
- Transaction deadline — How long the swap remains valid before it expires.
Approve the Token (First Time Only)
This step only applies to ERC-20 token swaps (e.g., USDC → ETH). If you are swapping ETH as the input token, skip to the next step.
Confirm the Swap
Click the Swap button to initiate the swap.A confirmation modal appears showing the full details of your swap:
The confirmation modal displays:
- Input and output token amounts with token icons
- Exchange rate at time of execution
- Price impact
- Minimum received after slippage
- Estimated gas cost (in ETH and USD)
Sign in Your Wallet
Your wallet will prompt you to sign the transaction:
Confirm the signature or transaction in your wallet.
- For ERC-20 input tokens: You will sign an EIP-712 message (a signature, not a transaction). This is gasless — you do not pay gas at this step.
- For ETH input: You will sign and submit an on-chain transaction. This requires gas.
Receive Preconfirmation
Within seconds of signing, your swap is preconfirmed. A confirmation toast appears at the bottom of the screen:
Preconfirmed means Ethereum block builders on the mev-commit network have committed to including your swap in an upcoming block. This gives you near-instant confidence that your swap will settle — no need to wait for the full block to be produced.This is the core Fast Swaps experience: your swap feels instant.
What happens after preconfirmation?
What happens after preconfirmation?
After the preconfirmation, your swap progresses to full on-chain confirmation in the background. The toast will update once the swap is included in a finalized Ethereum block. You do not need to wait for this — the preconfirmation is your signal that the swap is done.
| Status | What It Means |
|---|---|
| Pending | Your swap intent has been submitted to FAST RPC |
| Preconfirmed | Ethereum block builders on mev-commit have committed to including your transaction — your swap is effectively done |
| Confirmed | The swap has been included in a finalized Ethereum block. Your output tokens are fully settled on-chain |
Swap Complete
Once fully confirmed on-chain, the toast updates with a link to the transaction on Etherscan.
Your output tokens are now in your wallet. The swap form resets, ready for your next trade.You have earned Fast Miles for this swap. Check your dashboard to see your accumulated miles and leaderboard ranking.
Earn Fast Miles
Every swap you make on Fast Swaps earns Fast Miles — mev rewards proportional to the value your swaps generate through Fast Protocol. The more you swap, the more miles you earn.View Dashboard
Check your Fast Miles balance, swap history, and leaderboard position.
Leaderboard
See how you rank against other Fast Swaps users.
Tips & Troubleshooting
My swap is taking a long time
My swap is taking a long time
Ethereum block times are approximately 12 seconds. Most swaps are preconfirmed within seconds and fully confirmed within 1-2 blocks (12-24 seconds). If a swap takes longer:
- Check your wallet for any pending transactions
- The swap may be waiting for a mev-commit opted-in proposer — see FAST RPC for details
- If the swap times out (exceeds your deadline), it will automatically cancel and your tokens will remain in your wallet
My swap failed — what happened?
My swap failed — what happened?
Common reasons for swap failure:
- Slippage exceeded — The price moved more than your slippage tolerance between quote and execution. Try increasing your slippage setting.
- Insufficient balance — Make sure you have enough of the input token plus ETH for gas (if swapping ETH).
- Deadline expired — The swap was not executed before the deadline. Try again with a fresh quote.
- Price impact too high — For large swaps, try splitting into smaller amounts.
I approved a token but still see the Approve button
I approved a token but still see the Approve button
Can I swap any token?
Can I swap any token?
Do I need ETH for gas?
Do I need ETH for gas?
- Swapping ERC-20 tokens (e.g., USDC → ETH): After the initial one-time Permit2 approval, subsequent swaps are gasless — you only sign a message.
- Swapping ETH (e.g., ETH → USDC): You submit an on-chain transaction and pay standard Ethereum gas fees.
- First-time token approval: The one-time Permit2 approval requires a small amount of ETH for gas.
What’s Next?
How Fast Swaps Works
Learn about the technical architecture, smart contracts, and mev reward mechanics behind Fast Swaps.
Fast Protocol Economics
Understand how mev is captured, distributed, and why users receive at least 90% of the mev their transactions generate.
FAST RPC
Learn about the FAST RPC that powers preconfirmations and mev capture for Fast Swaps.