What Uniswap Is
Uniswap is the largest decentralized exchange (DEX) — a set of smart contracts that let you swap tokens directly from your wallet, with no account, no KYC, and no company holding your funds. Instead of matching buyers and sellers through an order book, Uniswap uses an automated market maker (AMM): prices are set by pools of tokens supplied by other users. This guide shows you how to use it safely.
Self-custody means self-responsibility. On a DEX there is no support desk to reverse mistakes. Double-check everything.
How an AMM Works (In Plain English)
Each trading pair (say $ETH/USDC) has a liquidity pool holding both tokens. When you swap $ETH for USDC, you add $ETH to the pool and remove USDC; the ratio shifts and the price moves. Larger trades move the price more — this is price impact. Liquidity providers earn fees for supplying those tokens (covered in our liquidity guide).
Step 1 — Set Up a Wallet
You'll need a self-custodial wallet like MetaMask, funded with the network's gas token. See our MetaMask setup guide. Uniswap runs on Ethereum and several Layer-2s (Arbitrum, Base, Optimism, Polygon), where fees are far lower — consider using an L2 for small swaps.
Step 2 — Connect to the Official Site
- Type the official URL directly (app.uniswap.org) — never trust search ads, which are a common phishing vector.
- Click Connect and select your wallet.
- Approve the connection in your wallet — this shares only your public address.
Warning: Bookmark the real site. Fake Uniswap clones exist to drain wallets — learn to spot them in our phishing guide.
Step 3 — Make a Swap
- Select the token you're paying with and the token you want.
- Enter an amount — Uniswap shows the estimated output and price impact.
- Verify the token contract address for anything unfamiliar (see below).
- For a token's first use, approve it (a one-time permission), then confirm the swap.
- Pay the gas fee and wait for the transaction to confirm.
Step 4 — Understand and Control Slippage
Slippage is the difference between the expected price and the executed price, caused by market movement or low liquidity. In settings you can set a slippage tolerance:
- 0.1–0.5% for large, liquid pairs ($ETH, USDC).
- 1–3% may be needed for smaller tokens — but high tolerance invites bad fills.
- Setting it too high exposes you to sandwich attacks (a form of MEV) where bots profit at your expense.
Avoiding Scam Tokens
Anyone can create a token and a pool. Protect yourself:
- Only import tokens using the official contract address from the project's real site or a reputable aggregator.
- Beware tokens you can buy but can't sell (honeypots).
- Ignore unsolicited tokens that appear in your wallet — don't interact with them.
- Check liquidity and trading history; brand-new pools carry the most risk.
Gas Fees and Timing
- Ethereum mainnet fees spike during busy periods — check gas before swapping.
- Use Layer-2s for cheap swaps; bridge funds first if needed.
- Always keep some native gas token in your wallet, or transactions will fail.
After the Swap
Your new tokens appear in your wallet automatically (import by contract address if not). Review any approvals you granted and consider revoking unused ones periodically to reduce risk.
Final Thoughts
Uniswap gives you permissionless access to thousands of tokens straight from your wallet — powerful, but unforgiving of mistakes. Connect only to the official site, verify contract addresses, keep slippage sensible, and use Layer-2s to save on fees. Master these habits and DEX trading becomes a safe, everyday tool.