getting-started

Your first DEX swap (5 USDC → ETH on Base)

Cheap, fast, no API keys — the safest way to learn DEX swaps

10 min · beginner

What you'll have when finished

  • Have one real DEX swap on Base in your History
  • Know what each step asks for and why
  • Be ready to swap on Ethereum mainnet with confidence

Before you start

  • DEX swaps are NON-CUSTODIAL — we cannot undo a wrong swap. Double-check the To token address before signing
  • On Ethereum mainnet, gas can be $10-40 for a single swap. Use Base for learning ($0.01-0.05 gas)
  • NEVER paste a "support staff" wallet address. Legit support never asks you to send funds

Walkthrough

  1. Get a little USDC on Base

    You need a wallet (MetaMask works) with at least 5 USDC on Base AND a tiny amount of ETH on Base for gas (~$0.10 worth is plenty). Bridge from Ethereum or Coinbase via the Base bridge (bridge.base.org) or just withdraw USDC directly from Coinbase to Base — Coinbase supports native Base withdrawals.

    Success criteria: MetaMask shows ≥ 5 USDC on Base AND ≥ ~$0.10 of ETH on Base

  2. Open DEX Swap and connect your wallet

    DEX Trade → DEX Swap. Click the wallet button top-right and pick MetaMask (or whichever you use). The popup asks to connect — approve it. Your wallet address appears in the button.

    Success criteria: Your wallet address (0x… short form) is visible in the top-right corner

  3. Switch the chain selector to Base

    Top of the swap card — chain selector. Click and pick Base (🔵). If your wallet is on a different chain, you get a popup to switch. Approve the switch in your wallet. The popular token list now shows ETH + USDC for Base.

    Success criteria: The chain selector shows Base and the popular token list shows just ETH + USDC

  4. Set From = USDC, To = ETH, amount = 5

    From token: click and pick USDC. To token: click and pick ETH. Amount field: type 5. The interface shows "5 USDC" in the From slot.

    Success criteria: You see From=USDC 5, To=ETH (amount field empty for To — that fills in after quote)

  5. Get Best Quote

    Click Get Best Quote. Within 2-3 seconds you see the quote panel: best aggregator name (0x, Paraswap, or 1inch), execution price (something like 1 ETH ≈ X USDC), gas estimate (should be < $0.10 on Base), minimum received, price impact %. Below that, all 3 aggregators side-by-side with the savings.

    Success criteria: Quote panel visible with a non-zero ETH output (you should receive roughly 5 / current ETH price)

  6. Leave slippage at 0.5%, click Confirm Swap

    Slippage default is 0.5% which is correct for ETH (blue chip). Click Confirm Swap. MetaMask pops up TWO times: first an Approval transaction (you give Paraswap/0x permission to pull your USDC — gas ~$0.01-0.03), then the Swap transaction itself. Sign both.

    Success criteria: Both signatures complete and the page shows "Swap submitted" with a tx hash link

  7. Watch confirmation + read MEV analysis

    Confirmation usually lands within 5-10 seconds on Base. The swap card updates to confirmed. Switch to the History tab — your swap is the top row showing actual ETH received, MEV savings vs worst aggregator, and a link to the Basescan block. Your wallet now shows the new ETH balance.

    Success criteria: History tab shows your swap as confirmed with the actual ETH amount received and a valid Basescan link

What's next

You did a real swap. Next: try a Limit Order on the same page ("Buy ETH on Base when it drops 5%") — that uses the dedicated [[dex-limit-orders-first-order]] flow. To learn recurring buys, see DEX DCA. To learn MEV-protected swaps on Ethereum mainnet, repeat this guide but pick chain = Ethereum and pay attention to the gas estimate before signing.