How to Swap Tokens on Uniswap (MetaMask Step-by-Step 2026)

What you'll need#

• A wallet extension or app: MetaMask is the most popular; Rabby and Coinbase Wallet work the same way.
• The seed phrase backed up on paper or metal — not on your phone, not in a screenshot, not in iCloud (see how to create a crypto wallet).
• Some ETH (or the network's native token) for gas. Even if you're swapping USDC to USDT, you need a small amount of ETH/MATIC/ARB to pay gas.
• The tokens you want to swap from already in the wallet.

If you don't have any crypto in self-custody yet, the typical first move is: buy on a CEX (Binance, Coinbase, Kraken) → withdraw to your MetaMask address → then swap on Uniswap. See how to transfer crypto between exchanges for the withdrawal mechanics (same flow applies for CEX → wallet).

Step 1 — Open Uniswap (the safe way)#

Type uniswap.org into the address bar yourself. Do not Google "Uniswap" and click the first result — sponsored links to typosquats (uniiswap.org, uniswap-app.io, etc.) are a constant phishing vector.

Bookmark the real URL after you've typed it correctly once. Use the bookmark from then on.

The site will prompt: "Connect Wallet." Click it.

Step 2 — Connect MetaMask#

1. A popup shows wallet options. Click MetaMask (or your wallet).
2. MetaMask itself opens a confirmation: "Uniswap wants to connect to your wallet." Review the URL shown in the MetaMask popup matches app.uniswap.org (or uniswap.org).
3. Click Connect.
4. You're now connected. Your wallet address appears top-right of Uniswap.

What "connect" actually means: Uniswap can now read your address and see your token balances. It cannot move any funds. Moving funds always requires a separate transaction confirmation in MetaMask.

Step 3 — Pick the right network#

The Uniswap interface shows the current network in the top-right corner (Ethereum, Polygon, Arbitrum, Optimism, Base, BSC, Avalanche).

For most beginners on small swaps, Arbitrum or Base is the right choice — same Uniswap, ~30× cheaper gas. To switch:

1. Click the network selector in Uniswap (or in MetaMask).
2. Pick the destination network.
3. MetaMask prompts: "Switch network?" — confirm.

If your tokens are on a different network than you want to swap on, you'll need to bridge them first (Uniswap doesn't bridge for you; use a bridge like Across, Stargate, or the official Arbitrum/Base bridge).

Step 4 — Pick the input and output tokens#

1. Top field (You pay): click the token selector, search by symbol (e.g., "USDC") or paste the contract address.
2. Bottom field (You receive): same — pick the destination token.
3. Verify the token contract address against the project's official website or CoinGecko. This is critical for tokens you haven't traded before — fake tokens with identical symbols are a common scam. The contract address is the only thing that can't be faked.
4. Enter the amount you want to swap.

Uniswap displays the estimated output, the price impact, and the best route (it may go USDC → ETH → TARGET rather than direct, if that's cheaper).

Step 5 — Check slippage and price impact#

Click the gear icon to see settings:

• Max slippage: 0.5% is the default. Acceptable for major pairs (ETH/USDC, ETH/USDT, WBTC/ETH). Volatile or thin pairs may need 1-3%. Slippage above 5% is almost always a sign the pool is too thin or the token is a trap.
• Transaction deadline: 30 minutes default — fine. Sets how long the transaction is valid; if it doesn't execute in that window, it auto-cancels.

Price impact is shown directly under the swap quote. It's how much your trade itself moves the price.

• Under 1%: normal for liquid pairs.
• 1-5%: acceptable on smaller pairs.
• >5%: the pool is thin. Either swap less, swap on a different DEX, or skip the token entirely.

Step 6 — Approve the token (first time only, ERC-20 only)#

If this is the first time you're swapping a particular ERC-20 token from this wallet, Uniswap will show "Approve [TOKEN]" before "Swap."

1. Click Approve.
2. MetaMask popup: "Allow Uniswap to use your [TOKEN]?"
3. Edit the amount to the exact swap amount. MetaMask defaults to "Unlimited" — this is the safer default to override. If a malicious contract ever gains access, unlimited approval lets it drain the entire balance of that token from your wallet forever.
4. Confirm. Wait for the approval to be mined (10-30 seconds on Arbitrum/Base, longer on mainnet).
5. The button changes to Swap.

Note: this approve step doesn't exist for ETH itself, only for ERC-20 tokens (USDC, USDT, ARB, etc.).

Step 7 — Confirm the swap#

1. Click Swap.
2. Uniswap shows a confirmation screen with the final numbers (you pay X, you receive ~Y, fee Z).
3. Click Confirm Swap.
4. MetaMask popup opens. Carefully review:
   • Network matches what you chose
   • From address is your wallet
   • To address is the Uniswap router (0x... — Uniswap displays the official router address on its site)
   • Gas fee is reasonable
5. Click Confirm in MetaMask.

The transaction broadcasts to the network. The Uniswap interface shows "Pending" then "Success."

You can verify on a block explorer (etherscan.io for Ethereum, arbiscan.io for Arbitrum, basescan.org for Base):

• Click the transaction hash from the success popup
• Confirm the swap output matches your expected amount

The new tokens are now in your wallet.

Adding a new token to MetaMask display#

By default, MetaMask shows ETH plus a handful of major tokens. New tokens may not show up automatically:

1. Open MetaMask.
2. Click "Import tokens" at the bottom of the assets list.
3. Paste the token's contract address.
4. MetaMask auto-fills the symbol and decimals.
5. Verify the symbol matches what you expect — never trust the popup without checking.
6. Click Import.

The token now shows in your wallet balance.

What can go wrong#

• Swap fails ("transaction reverted"). Usually slippage too tight — the price moved more than your max during the few seconds the transaction was in flight. Increase slippage slightly and retry.
• Swap goes through but you got dramatically less than expected. Either the pool was extremely thin (you got sandwich-attacked) or the token has hidden tax/fee logic. Most "honeypot" scam tokens trigger this on sell — they let you buy normally but the sell transaction returns 1% of what you should get.
• Token doesn't show in wallet. It's there on-chain; you just need to import it manually (above).
• MetaMask shows a different network than Uniswap. Switch in either app — they'll sync. If they don't, refresh Uniswap.
• Gas estimate is unreasonably high. Either the network is congested or the contract is malicious. If you're swapping on a reputable token and gas is suddenly 5× normal, close the popup and try again later.

Common Uniswap mistakes to avoid#

• Clicking the first Google result for "Uniswap." Type the URL manually or use a bookmark.
• Granting unlimited token approval. Always cap to the exact amount you're swapping.
• Skipping the contract-address check on new tokens. Symbol "USDC" can be a real USDC or a worthless fake — the contract address is the only ground truth.
• Setting slippage to 10%+ to "force the trade through." This is exactly what sandwich bots want. If you need that much slippage, something is wrong with the pool.
• Swapping right before a major news event. Slippage and gas spike during volatility. Wait 10-20 minutes after a big move if you're not in a hurry.
• Storing the seed phrase in a screenshot, iCloud, or any internet-connected place. That phrase is the wallet. Anyone who sees it can drain it instantly.

Bottom line#

Uniswap swaps come down to four checks every time: the URL is real, the network is right, the token contract is real, and you understand what MetaMask is asking you to sign. Do those four checks and the protocol itself does its job reliably. Skip any one of them and you're the user who got drained — not because Uniswap failed but because the safety steps exist for a reason.

For small swaps, prefer Arbitrum or Base to keep gas under $1. For large swaps, the Ethereum mainnet's deeper liquidity sometimes justifies the higher gas.

What to read next#

• What is a crypto wallet — the mechanism that makes self-custody work.
• How to create a crypto wallet step by step — MetaMask install and seed-phrase backup.
• How to keep crypto safe for beginners — the broader on-chain safety habits.
• Common crypto scams 2026 — phishing, drainers, and approval scams in detail.
• DEX vs CEX for beginners — when to use Uniswap vs Binance/Coinbase.
• How to set up a Ledger hardware wallet — for protecting larger on-chain balances.