Blockchain technology has undergone significant evolution since the early days of Bitcoin. Today, blockchains are becoming increasingly efficient with the development of new protocols designed to address specific issues. These secondary protocols are known as Layer 2 (L2) networks, and they are among the top technologies driving scaling in decentralized finance (DeFi).
What Are Blockchain Layer 2 Networks?
Blockchains operate on protocols, which are sets of rules or standards that define how data is secured and recorded, as well as how nodes interact with one another. Blockchain users, particularly crypto traders, rely on these protocols for efficient transactions, whether on an on-chain or off-chain crypto trading platform, where they trade digital assets.
Sometimes, the primary protocols (L1) necessitate an upgrade when they fail to meet the dynamic demands of the blockchain network, such as improved speed, increased transaction capacity, and enhanced security. Such upgrades usually come in the form of a new set of protocols built on the primary protocols.
These secondary protocols, known as Layer 2 networks, address the issues that the blockchain faces.
How Layer 2 Networks Work
Layer 2 networks operate by taking transactions off the main blockchain (off-chain), shifting the heavy processing to faster and smaller chains, and then bringing the results back to the main chain for settlement.
The primary purpose of layer 2 protocols is to enhance transaction speed and reduce transaction fees (also known as gas fees). Think of the primary blockchain (layer 1) as a highway congested with traffic, and the layer 2 network as a fast road built on top of the highway.
There are five main types of layer 2 solutions:
- Rollups: These networks bundle transactions off-chain and, once completed, return a compressed version to the L1
- State Channels: These solutions utilize smart contracts to lock funds and update the transaction status off-chain. This enables multiple off-chain transactions while requiring only the final state in the channel to be recorded.
- Sidechains: Sometimes, L2s are sidechains, which are independent blockchains that run in parallel to the L1, acting as a form of L2 solution through a two-way peg.
- Plasma: Plasma chains focus on independent child/nested chains deployed and managed on the L1 blockchain. Think of plasma chains as clones within a hierarchical blockchain ecosystem, with each blockchain maintaining its own independent security and consensus system.
- Hybrids: Hybrids combine features of two or more L2s, making them suitable for various blockchain protocols.
Over the years, developers have rolled out Layer 2 (L2) updates for blockchains, enhancing the networks to meet the growing demand for speed and lower transaction costs. The increasing adoption of cryptocurrency in real-world applications, particularly in DeFi, makes Layer 2s crucial for blockchains.
Why DeFi Needs Layer 2 Scaling
DeFi enables peer-to-peer financial services, such as lending, trading, and borrowing, by using smart contracts for execution. And, as an emerging financial system built on blockchain, DeFi brings speed, accessibility, transparency, and efficiency to the financial sector.
Although Bitcoin is the foundation of decentralization, Ethereum became the first true DeFi blockchain, paving the way for others, such as Polygon, Cardano, Uniswap, PancakeSwap, BNB, Solana, and Polkadot.
These blockchains were built or forked from existing chains and designed to introduce a new dimension of DeFi while addressing existing deficiencies in the space. However, many of them have faced challenges, such as network congestion and the resulting high gas fees, necessitating the use of Layer 2 solutions for scaling.
Here is how L2 scaling improves DeFi:
- Increased transaction speed: L2s increase transaction speeds from less than 20 TPS (transactions per second) to thousands or hundreds of thousands of TPS. For example, Ethereum 2.0, an L2 upgrade, can process up to 100,000 TPS compared to the L1’s 15 TPS. This near-instant speed reduces congestion and allows efficient transactions.
- Lower transaction costs: Bundling multiple transactions enables L2s to significantly reduce transaction costs to pennies, rather than the typical high gas fees.
- Improved user experience: Lower transaction costs and faster speeds improve user experience for traders and DeFi enthusiasts. Traders can avoid irritation caused by slow transactions, and on-chain trading is faster.
- Enhanced deployment and scalability: DeFi developers now deploy decentralized applications (dApps) primarily on Layer 2s (L2s) and newer blockchains, which offer L2-like efficiency. Developers using the L1s are also finding it easier to scale their operations and support interoperability.
- Improved access to liquidity pools: Liquidity pools are vital to DeFi, as they enable seamless trading, lending, staking, and other services through crowdfunding. The increased speed and lower costs of L2 transactions make it easier for DeFi users to access liquidity pools.
Popular Layer 2 Technologies and Protocols
Although many Layer 2s (L2s) exist across blockchains, with Ethereum having the most protocols, the Ethereum Layer 2s include Polygon, Arbitrum, Optimism, zkSync, StarkNet, Immutable X, MetisDAO, Mantle, dYdX, SKALE, and Shibarium.
Bitcoin also has several Layer 2 solutions, including the Lightning Network. There are also Avalanche Subnets, Dymension, Base L2s, and BNB Chain L2s, including opBNB.
The Impact of Layer 2 on the Future of DeFi
Layer 2 solutions are already impacting DeFi in several ways, primarily by enhancing transaction speed, reducing costs, and facilitating cross-chain interoperability. Examples include HyperLiquid, a perpetual DEX, which hit $300 billion in trading volume by mid-year. Centrifuge and Yearn Finance are other solutions built on L2s that are scaling their services in 2025. These improved features are laying a solid foundation for DeFi growth and scalability in the future. Layer 2s will:
- Catalyze mass adoption of DeFi: Institutional adoption of DeFi will increase as corporate organizations embrace the speed and security of smart contracts. Layer 2s will drive this as they improve on L1 features.
- Spur the growth of liquidity pools: As more people adopt DeFi, the number of liquidity pools is expected to increase. This will benefit traders, as crypto prices will be more stable. Stakers and farmers on various projects will also get more returns on their locked funds.
- Develop the DeFi market/apps: All of these will spur the development of DeFi solutions. Developers will roll out more projects addressing human needs, and existing ones can scale up to meet the growing demand.
L2 Solutions in Action
Layer 2 solutions have been a game-changer for DeFi over the last few years. And in 2025, L2s are playing crucial roles in how DeFi solutions scale. They make it easier to build new apps, trade cryptocurrency, and use DeFi services without incurring high costs or experiencing long wait times. The future of DeFi looks bright: Layer 2 technology is giving it the tools needed to compete with traditional finance and serve millions of users around the world.
