Uniswap

Uniswap is the protocol that defined the modern decentralized exchange. Launched in November 2018 by Hayden Adams, it replaced the order book with an automated market maker (AMM), where prices are set algorithmically by the ratio of assets inside pre-funded liquidity pools. Anyone can swap tokens, list a new market, or become a liquidity provider without asking for permission — a design that turned Uniswap into core DeFi infrastructure.

The protocol has evolved through several major versions. Uniswap v2 popularized the simple x*y=k pool, v3 introduced concentrated liquidity, letting providers allocate capital to specific price ranges for dramatically higher capital efficiency, and v4 added 'hooks' — smart contracts that let developers customize pool behavior such as dynamic fees, on-chain limit orders and custom oracles. The interface now supports swapping across Ethereum, Arbitrum, Base, Optimism, Polygon, BNB Chain and Unichain, the team's own DeFi-focused L2.

Uniswap is governed by holders of the UNI token, which controls the protocol treasury and fee parameters. With the deepest liquidity of any DEX, industry-leading security track record and integrations into virtually every wallet and aggregator, Uniswap remains the default starting point for on-chain trading — though swappers still pay Ethereum gas fees on mainnet and face MEV/slippage on volatile pairs.