Quick answer
To swap on Uniswap: connect your MetaMask wallet at app.uniswap.org, select the token you are swapping from (e.g. ETH) and the token you want (e.g. USDC), enter the amount, review the rate and estimated gas fee, click Swap, and confirm in MetaMask. You need some ETH in your wallet for gas fees even when swapping other tokens.
What is Uniswap and how does it work?
Uniswap is a decentralised exchange protocol built on Ethereum. It launched in November 2018 and has since processed over $2 trillion in cumulative trading volume. Unlike traditional exchanges that match buyers with sellers, Uniswap uses Automated Market Makers (AMMs) — pools of tokens that anyone can trade against.
Anyone can provide liquidity to Uniswap by depositing token pairs into a pool and earning a share of the trading fees generated by that pool. Liquidity providers earn between 0.01% and 1% of every trade, depending on the fee tier of the pool.
Uniswap V3 (the current main version) introduced concentrated liquidity — allowing liquidity providers to specify price ranges within which their liquidity is active, making capital far more efficient. Uniswap V4, released in 2024, introduced 'hooks' — customisable logic that can be attached to pools for advanced use cases.
What do you need before using Uniswap?
- 01
A non-custodial wallet
MetaMask is the most compatible. Trust Wallet, Coinbase Wallet, and most other non-custodial wallets also work. You cannot use Uniswap from a centralised exchange account like Coinbase — you need your own wallet.
- 02
ETH for gas fees
Every transaction on Ethereum costs gas, paid in ETH. Even if you are swapping USDC for USDT, you need ETH to pay the transaction fee. On Ethereum mainnet, typical swap gas fees range from £3-£30 depending on network congestion. On Layer 2 networks like Arbitrum, gas is often under £0.10.
- 03
The token you want to swap
Load your wallet with the token you want to swap from. If you want to swap ETH for USDC, you need ETH in your wallet. If you want USDC for USDT, you need USDC. Buy from a centralised exchange first, then send to your wallet.
- 04
Correct network selected in MetaMask
Make sure MetaMask is set to the network where Uniswap is deployed and where your tokens exist. If your ETH is on Ethereum Mainnet, connect MetaMask to Ethereum Mainnet. If your funds are on Arbitrum, connect to Arbitrum.
Step-by-step: how to make your first Uniswap swap
- 01
Go to app.uniswap.org
Bookmark this URL. Only ever use app.uniswap.org. There are phishing sites designed to look identical to Uniswap that drain your wallet the moment you approve a transaction. Check the URL every time.
- 02
Connect your wallet
Click 'Connect' in the top right. Select your wallet (MetaMask, Coinbase Wallet, etc.). A wallet popup will ask you to approve the connection to Uniswap — click Connect. This costs no fee.
- 03
Select the token you are swapping from (You pay)
In the top field, choose what you are selling. ETH is the default. If swapping another token, click the token selector and type the token name or paste its contract address.
- 04
Select the token you want to receive (You receive)
In the bottom field, choose what you want. Type the name or paste the exact contract address from the official project website. For common tokens like USDC and USDT, Uniswap's default list is reliable.
- 05
Enter the amount
Type how much of the sell token you want to spend, or how much of the buy token you want to receive. Uniswap calculates the other amount automatically based on current pool prices.
- 06
Review the swap details
Before clicking Swap, review: the exchange rate (shown below the input fields), minimum received (the worst price you will accept, based on slippage tolerance), the price impact (how much your trade moves the price), and the network fee (gas cost estimate).
- 07
Click Swap
Uniswap shows a confirmation summary. Review it one final time, then click 'Confirm Swap'.
- 08
Approve in MetaMask
MetaMask opens showing the transaction details and gas fee. Review it carefully. If you are happy, click 'Confirm'. If the gas fee looks unusually high, you can cancel and try later when the network is less congested.
- 09
Wait for confirmation
Ethereum transactions typically complete in 15-60 seconds. A 'Transaction submitted' notification will appear. Click the transaction hash to track it on Etherscan. Once confirmed, your new token appears in MetaMask.
First-time swap of a specific token? You may see an 'Approve' step before the Swap. This is a one-time permission allowing Uniswap to access that token in your wallet. It costs a small gas fee. Only the swap transaction moves your funds.
What is slippage and how should you set it?
Slippage is the difference between the price you see when you initiate a swap and the price at which it actually executes. This happens because on-chain prices move block-by-block, and the time between submitting your transaction and it being confirmed means the price may shift.
Uniswap lets you set a slippage tolerance — the maximum price movement you will accept. If the actual price moves beyond your tolerance, the transaction reverts and you only lose the gas fee.
| Slippage setting | When to use | Risk |
|---|---|---|
| 0.1% | Large-cap stable pairs (ETH/USDC, USDT/USDC) | Trade may fail if any movement |
| 0.5% | Standard for most major token pairs | Good balance for most trades |
| 1-3% | Less liquid pairs, volatile markets | Higher chance of worse price |
| 5%+ | Very illiquid tokens, emergency trades | Significant price impact possible |
Setting slippage above 5% on unknown tokens is a serious red flag. Scam tokens (honeypots) sometimes require you to set very high slippage to buy — they are designed to prevent you from selling. If you see a token that 'only works' with slippage above 10%, it is almost certainly a scam.
How to spot and avoid scam tokens on Uniswap
Because anyone can create and list a token on Uniswap, it is full of scam tokens. The most common types are rug pulls (developers drain liquidity and disappear), honeypots (you can buy but not sell), and copycat tokens (named identically to legitimate projects).
- 01
Always verify the contract address
Before buying any token on Uniswap, copy the official contract address from the project's official website (not from Telegram, Discord, or Twitter). Paste this exact address into Uniswap rather than searching by name. A scam token can have the exact same name as a real one.
- 02
Check the token on CoinGecko or Etherscan
Search the contract address on CoinGecko (coingecko.com) or Etherscan (etherscan.io). Legitimate projects will appear with verifiable information. Newly created tokens with no CoinGecko listing, no website link, and no verified contract code are extremely high risk.
- 03
Check liquidity depth
On Uniswap, you can see the total liquidity in a pool. A pool with less than $100,000 in liquidity means your trade will have enormous price impact and the token is easy for bad actors to manipulate.
- 04
Look at the token holder distribution
On Etherscan, view the token's holders tab. If one or two wallets hold 50%+ of the token supply, this is a red flag — those holders could dump their position and crash the price at any time.
- 05
Never buy based on social media hype alone
Discord servers, Telegram groups, and Twitter/X are full of coordinated pump-and-dump schemes. Always do independent research before buying any unfamiliar token.
Using Uniswap on Layer 2 networks (Arbitrum, Base, Optimism)
Uniswap is deployed on multiple networks beyond Ethereum mainnet. For most users doing regular swaps, Layer 2 networks offer identical functionality with dramatically lower fees.
Switching to Arbitrum, Base, or Optimism in MetaMask allows you to interact with Uniswap at a fraction of the gas cost — often under £0.05 per swap. Liquidity for major pairs (ETH, USDC, USDT, WBTC) is deep on all major Layer 2 networks.
To bridge funds from Ethereum mainnet to a Layer 2, use official bridges: bridge.arbitrum.io for Arbitrum, bridge.base.org for Base, or app.optimism.io/bridge for Optimism. Bridging typically takes a few minutes and costs one mainnet gas fee.
Frequently asked questions
How much does it cost to swap on Uniswap?
There are two costs: Uniswap's trading fee (0.01% to 1% depending on the liquidity pool tier — 0.3% is most common for typical pairs) and the Ethereum network gas fee. On Ethereum mainnet, gas for a swap typically costs £5-30. On Layer 2 networks like Arbitrum or Base, gas for a swap is typically £0.01-0.50. The gas fee is the same regardless of swap size.
Can I swap tokens without ETH?
Not on Ethereum mainnet or Ethereum Layer 2 networks — ETH is required to pay gas fees for any transaction. Some networks use different native tokens for gas (e.g. BNB on BNB Chain, AVAX on Avalanche), but Ethereum and its Layer 2s always use ETH for gas.
What is 'price impact' on Uniswap?
Price impact is how much your specific trade moves the price, shown as a percentage. A 0.1% price impact means your trade causes the price to move 0.1% against you. Large trades in low-liquidity pools can have price impacts of 10-30%, meaning you receive significantly less than the displayed rate. Always check price impact before confirming large trades.
What is a 'failed transaction' and do I still pay gas?
Yes. If a transaction fails (e.g. due to slippage exceeding your tolerance, or an error in the smart contract), the gas fee is still charged because the network still processed the attempt. The tokens are returned to you. Failed transactions are annoying but you do not lose your principal, only the gas fee.
What is Uniswap governance and the UNI token?
UNI is Uniswap's governance token. Holders can vote on proposed changes to the protocol — fee structures, treasury spending, new features. UNI does not currently give holders a share of Uniswap's trading fees, though this has been actively debated. UNI was airdropped to early users in September 2020 — the most famous airdrop in DeFi history.