Ethereum's limitations in scalability and high gas fees have driven the need for Layer 2 (L2) solutions. L2 blockchains are built on top of the Ethereum mainnet, inheriting its security while offering improved scalability and lower transaction costs.

Here are four L2 blockchains:

Polygon

Polygon is a pioneering L2 solution utilizing various scaling techniques, including Plasma, Optimistic Rollups, and zk-Rollups. It aims to provide a multi-chain system for building and connecting Ethereum-compatible blockchain networks. Polygon supports a wide range of decentralized applications (dApps) across domains like DeFi, NFTs, gaming, and more.

Arbitrum

Developed by Offchain Labs, Arbitrum is an Optimistic Rollup solution that enables smart contracts to run securely and efficiently on Ethereum. It uses an advanced compression technique called Recursive Proof Composition, allowing for high throughput and low transaction costs. Arbitrum supports popular dApps like Uniswap, Chainlink, and Sushi.

Optimism

Optimism is an Optimistic Rollup solution that scales Ethereum dApps without compromising security. It introduces a novel fraud-proof mechanism called Optimistic Virtual Machine (OVM), enabling fast transaction confirmations. Optimism supports various dApps, including DEXs like Synthetix and lending platforms like Aave.

Starknet

Starknet is a decentralized L2 solution powered by StarkWare's zk-Rollup technology. It utilizes zero-knowledge proofs to bundle and validate transactions, enabling high scalability and low fees. Starknet supports general-purpose smart contracts, making it suitable for various applications, including DeFi, NFTs, and gaming.

These L2 blockchains leverage different scaling techniques, offering trade-offs in terms of security, decentralization, and throughput. As the adoption of Ethereum dApps continues to grow, L2 solutions like these will play a crucial role in addressing scalability challenges while inheriting the security of Ethereum mainnet.