Layer-2 Scaling Solutions for Blockchain: An Expert’s Guide

Layer-2 feature image

Since its birth with Bitcoin in 2009, blockchain technology has promised to revolutionize various industries, from finance to supply chain, healthcare, and beyond. While the promise of blockchain is excellent, scalability is one key barrier to its widespread adoption.

Consider a thriving metropolitan metropolis with only a two-lane motorway for traffic. Traffic congestion is unavoidable as the city grows and the number of vehicles increases, generating delays and frustration. This describes the present situation of most blockchains.

Bitcoin, which can only perform 4.6 transactions per second (tps), and Ethereum, which can process approximately 15 tps, are susceptible to hours-long delays, especially during congestion, which can push their fees upwards of $50.

Such high fees render small-value transactions, like in-game purchases, impractical. In contrast, traditional systems like Visa, with about 1,700 tps, process transactions within seconds. Their percentage-based fees make even microtransactions economical, ensuring feasibility for activities like gaming.

This considerable difference in processing speed is one of the biggest barriers to blockchain’s widespread adoption. The scalability trilemma of blockchain has long been a study emphasis in the community, balancing decentralization, security, and scalability.

The introduction of Layer-2 scaling methods can help to solve this problem. Layer-2 solutions, like adding multi-lane motorways to our city to handle more traffic and relieve congestion, are aimed to increase the capacity of blockchain networks.

This article will explain the concept and importance of Layer-2 blockchain networks, as well as look into several Layer-2 scaling methods.

What are Layer-2 Blockchain Networks?

Layer-2 blockchain networks, also known as “Layer-2 solutions” or “off-chain solutions,” are protocols that expand a blockchain’s (Layer-1) processing capacity without modifying the underlying layer.

They function ‘on top’ of the original blockchain, utilizing it for security and finality but performing transactions off-chain for higher throughput and lower costs.

The inherent limitations of Layer-1 blockchains necessitate the development of Layer-2 solutions. As previously stated, Layer-1 networks such as Bitcoin and Ethereum struggle to handle a high volume of transactions.

As a result, transaction times slow and prices rise, rendering these networks unsuitable for widespread, daily use.

Layer-2 solutions reduce the burden by offloading the majority of transactions from the main chain, allowing for faster processing times and reduced costs. This not only improves the user experience but also allows for more complex applications that demand high-frequency, low-cost transactions, extending the utility of blockchain technology.

Layer-2 solutions are critical and cannot be emphasized more. They have the potential to solve the scalability trilemma,’ so considerably contributing to the widespread use of blockchain technology.

We’ll learn how potential Layer-2 scaling solutions might affect the future of the blockchain ecosystem as we delve deeper into them.

Layer-1 Blockchains and Scalability

layer-1 blockchain

Picture the blockchain world to be a vast multi-story structure. Layer-1 blockchains serve as the underlying base upon which everything else is built. They are the core, decentralized networks where blockchain magic initially manifests itself.

They are the crypto world’s pioneers, with Bitcoin and Ethereum being the most well-known names.

The underlying primary blockchain network is referred to as Layer-1. Layer-1 transactions are handled and safeguarded directly on the network’s blockchain. It is here, free from the grip of a central authority, that the raw promise of blockchain technology – decentralization, immutability, and transparency – shines brightly.

Nonetheless, despite their revolutionary benefits, Layer-1 blockchains come with a set of problems.

Do Layer-1 Blockchains Address Blockchain Network Scalability Issues?

You are at a rock concert, trying to upload a video to your social media account via a poor Wi-Fi connection. Isn’t the upload taking forever because of the overloaded network? That’s the narrative of Layer-1 blockchains: innovative, yet hampered by scalability.

While Layer-1 blockchains such as Bitcoin and Ethereum have proven revolutionary, they have prioritized security and decentralization. Every transaction requires all nodes in the network to establish a consensus, making these networks both secure and sluggish.
As more users join the network and more transactions need to be completed, this strategy becomes troublesome.

For example, Bitcoin’s network can handle approximately 4.6 transactions per second, while Ethereum’s network can handle approximately 15. In comparison, typical banking systems such as Visa process around 1,700 transactions per second.

So, does Layer-1 address the scalability problem? The short answer is ‘no‘.

They were not developed with scalability in mind. While Ethereum has addressed this issue with its Ethereum 2.0 upgrade and sharding strategies, the scalability issue remains mostly in Layer-1. It’s like attempting to cram an entire ocean of transactions into a single jug.

This constraint prompted the development of creative ways to improve scalability while maintaining security and decentralization, giving rise to Layer-2 blockchain networks.

Layer-1 vs Layer-2 Blockchains: How are They Different?

layer-1 vs layer-2 scaling solutions

Layer-1 and Layer-2 blockchains provide distinct functions and are essential components of the blockchain ecosystem. Comparing them is analogous to comparing the base of a home to the top floors: both are necessary, but they serve different functions.

Layer-1 Blockchains serve as the basic layer, ensuring security, decentralization, and transparency. They are the fundamental building blocks of blockchain technology, encapsulating the fundamental concepts of this revolutionary technology.

Layer-2 blockchains, on the other hand, are like the architects who labor to improve the functioning of the solid Layer-1 foundation. They scale by processing transactions off-chain and then uploading the completed state to the main chain. This results in speedier transactions and lower fees, allowing the blockchain to run complicated applications and paving the way for widespread adoption.

While Layer-1 blockchains are the blockchain’s heart and soul, Layer-2 networks are its brains, delivering the innovative solutions needed for the blockchain to properly scale and reach its full potential.

Advantages of Layer-2 Solutions

Increased Transaction Speed

Layer-2 solutions handle transactions off-chain, boosting transaction speed dramatically. It’s similar to having an express checkout line at a supermarket for faster, more efficient transactions.

Cheaper Transaction Fees

Because off-chain transactions do not affect the main network, they result in cheaper fees, making micropayments possible. It’s the same as sending a text message instead of snail mail – speedier and less expensive!

Application Scalability

Layer-2 solutions enable additional transactions to be handled concurrently by offloading the main chain. They expand the two-lane blockchain highway to eight lanes.


Some Layer-2 technologies enable transactions across distinct Layer-1 blockchains through cross-chain interoperability. This enables the creation of a uniform, integrated blockchain ecosystem.


Layer-2 solutions are adaptive and versatile. They can be created and optimized for unique use cases without affecting the underlying layer, boosting blockchain network functioning.

Read more on Blockchain: NFT Platform: A Guide to Creating Your Digital Marketplace

Drawbacks and Challenges of Layer-2 Solutions

Security Issues

While Layer-2 solutions rely on the Layer-1 network’s security, the additional layer can create new vulnerabilities. As these systems evolve, they must incorporate effective security measures.


Layer-2 solutions necessitate increased technical complexity. This can be a hurdle for consumers and developers who are unfamiliar with Layer-2 protocols.


It can be difficult to persuade consumers and developers to switch from a familiar Layer-1 environment to a Layer-2 solution. It takes knowledge, trust, and evidence of advantages.


While some Layer-2 systems provide interoperability, others may contribute to chain isolation, in which transactions cannot readily transition from one Layer-2 solution to another.

Data Availability

There may be issues with data availability and consistency in certain Layer-2 solutions. All parties must have constant access to the necessary data.

Deep Dive into Layer-2 Scaling Solutions

Layer-2 solutions are like a toolbox, each tool designed for a specific type of job, but together, they make the entire building process efficient. There are several types of Layer-2 solutions, each with unique features, strengths, and weaknesses.

Let’s take a closer look at some of these innovative tools that are reshaping the blockchain landscape.

State Channels

State channels are analogous to opening a bar tab: you execute an initial transaction (open a tab) on the blockchain, then conduct many off-chain transactions (order drinks), and eventually settle by updating the blockchain with the net conclusion (close the tab).

A state channel is a two-way communication channel built on the blockchain between members. Participants can freely transact within this secret channel, and these transactions are instant and only known to the persons involved. When the channel is closed, only the final state is stored on the blockchain.


  • Instant transactions: Because state channels are performed off-chain, they offer nearly immediate transactions.
  • Lower fees: Because transactions are off-chain, network fees are avoided except when the channel is opened and closed.
  • Privacy: Only the opening and closing trades are public. The rest are only known to the participants.


  • Limited Participants: State channels are excellent for transactions between known, frequent interactors but less beneficial for one-time or occasional transactions.
  • Online requirement: For a channel to function, all participants must be online, which may be a constraint in particular use cases.
  • Capital lockup: Funds are locked in the channel until it is closed, which may result in inefficient capital utilization.

Real-world Examples

  • Lightning Network: The Lightning Network is a Bitcoin state channel implementation that enables quick, low-cost transactions.
  • Raiden Network: The Raiden Network is Ethereum’s version of state channels, to make payments fast, cheap, and scalable.
  • Celer Network: Celer Network is a generalized state channel network that aims to add Internet scale to present and future blockchains.

Zero-Knowledge Rollups

Zero-Knowledge Rollups (ZK-Rollups) are the masters of condensing a 3-hour epic movie into a 2-minute summary while not leaving out any important details. They combine multiple transactions into a single one, significantly reducing the amount of data stored on-chain.

Using a technique known as Zero-Knowledge Proofs, they are still able to maintain full proof of the transaction’s validity.


  • Scalability: By bundling transactions, ZK-Rollups dramatically boost the blockchain’s scalability.
  • Security: They rely on the underlying Layer-1’s security, adding no new security issues.
  • Cost-effectiveness: When transactions are grouped, the cost per transaction is dramatically lowered.


  • Complexity: Zero-understanding Proofs are a sophisticated cryptographic technique that requires advanced understanding to implement.
  • Computation: The process of constructing Zero-Knowledge Proofs is computationally costly, which may limit transaction processing speed.

Real-world Examples

  • zkSync: zkSync is an easy-to-use ZK-Rollup platform for Ethereum that prioritizes scalability over security.
  • Hermes Network: Hermes Network employs ZK-Rollups to enable high-speed, low-cost Ethereum transactions.

Optimistic Rollups

ORs are similar to an ‘honor system’ in a library, where everyone is expected to return books on time. They work based on ‘optimism,’ presuming that all transactions are honest. If a transaction is challenged, the system investigates and, if required, penalizes the dishonest party.


  • Scalability: ORs boost transaction throughput by processing transactions off-chain and only providing a summary to the main chain.
  • Compatibility: ORs are compatible with Ethereum smart contracts, making them more accessible to developers.
  • Security: They rely on the Layer-1 network’s security, while the ‘challenge period’ protects against fraudulent transactions.


  • Waiting Periods: There is a ‘challenge period’ for disputing transactions. Transactions are not finalized during this time, which may cause delays.
  • User Experience: Non-technical users must actively monitor for fraudulent transactions, which can be a complex and demanding undertaking.

Real-world Examples

  • Optimism: Optimism is an Optimistic Rollup method for scaling Ethereum that is compatible with Ethereum’s developer tools and environment.
  • Arbitrum Rollup: Arbitrum Rollup is an Optimistic Rollup protocol that scales Ethereum by processing transactions off-chain and delivering a summary to the Ethereum mainnet.

What’s the Difference Between Optimistic Rollups and ZK-Rollups?

ZK-Rollups and Optimistic Rollups both try to boost transaction throughput by grouping many transactions. The major distinction is in how they assure the legitimacy of these transactions.

ZK-Rollups validate transactions before they are posted on-chain using Zero-Knowledge Proofs. This makes ZK-Rollups more computationally intensive, but it also results in faster transaction finality because there is no ‘challenge period.’

Optimistic Rollups, on the other hand, function on the premise of ‘optimism,’ presuming all transactions are honest unless proven otherwise. This reduces calculation requirements but provides a ‘challenge period’ before transaction completion, potentially resulting in wait delays.

Both solutions have advantages and disadvantages, and their selection is determined by the use-case’s specific requirements.


Sidechains function similarly to parallel roads on a motorway, providing an alternate path for some traffic. They are distinct blockchains that coexist with the main blockchain, allowing assets to be exchanged between the two.
Sidechain operations are processed independently of the main chain, lessening the burden on the main chain.


  • Scalability: Sidechains boost the network’s overall transaction capacity by unloading transactions off the main chain.
  • Innovation and Flexibility: Sidechains can implement distinct features and regulations from the main chain, fostering innovation.
  • Interoperability: Assets can be transferred back and forth between the main chain and the sidechains.


  • Security: Because of lower levels of decentralization and participation, sidechains may have weaker security than the main chain.
  • Complexity: Managing assets across various chains adds complexity for consumers and developers.

Real-world Examples

  • Liquid Network: Liquid Network is a Bitcoin sidechain that enables speedier Bitcoin transactions and offers features such as confidential transactions.
  • xDAI Chain: xDAI is an Ethereum sidechain that employs DAI as its native money, providing rapid and cheap transactions.


Plasma is analogous to a tree sprouting off the main Ethereum blockchain, with each branch (child chain) handling its transactions. Each Plasma chain can use its consensus protocol, and only if a disagreement emerges is it brought to the Ethereum mainnet.


  • Scalability: Plasma greatly increases the transaction capacity of the Ethereum network by establishing child chains that handle transactions separately.
  • Efficiency: Plasma chains enable smaller, faster block confirmation times.


  • Complexity: Implementing and managing Plasma chains necessitates a high level of technological knowledge.
  • User Experience: To deposit and withdraw funds, users must often engage with the main chain, which might be time-consuming.

Real-world Examples

  • OMG Network: The OMG Network employs a version of Plasma to enable faster, cheaper transactions on the Ethereum network.
  • Matic Network (formerly Polygon): Matic initially used a customized version of Plasma on the Ethereum network for scalable asset transfers.

Lightning Network

The Lightning Network functions as a superhighway for Bitcoin transactions. It is a Layer-2 solution built on top of the Bitcoin blockchain, allowing users to construct payment channels between any two parties on that extra layer.

These channels can live indefinitely, and because they are set up between two persons, transactions will be very instantaneous, with fees that are extremely minimal or even non-existent.


  • Fast Transactions: The Lightning Network enables near-instantaneous transactions, which substantially improves over Bitcoin’s block period of 10 minutes.
  • Lower Fees: Transaction fees are greatly reduced, and in some cases abolished, making micro-transactions possible.
  • Scalability: It can handle a far higher volume of transactions, potentially millions per second.


  • Online Requirement: For transactions to take place, nodes must be online, which may be problematic for some users.
  • Complexity: Routing payments via the network can be difficult, particularly as the network develops in size.
  • Capital Lockup: Funds must be locked into channels and can only be released when the channel is closed.

Real-world Examples

  • Bitcoin Lightning Wallets: Several Bitcoin wallets, including BlueWallet and Eclair, accept Lightning Network payments, allowing for faster and cheaper Bitcoin transactions.
  • Bitrefill: With mobile top-ups, gift cards, and Lightning Network services for Bitcoin, Bitrefill enables users to live on cryptocurrencies.


StarkWare functions similarly to a high-performance blockchain engine. It employs Zero-Knowledge (ZK) Proof methods to improve blockchain scalability and privacy.

Its STARK technology delivers a powerful, scalable solution that allows blockchains to manage more transactions more effectively.


  • Scalability: StarkWare’s technology enables blockchains to process more transactions per second, dramatically improving scalability.
  • Privacy: StarkWare also improves transaction secrecy by utilizing ZK-STARKs.
  • No Trusted Setup: Unlike previous ZK systems, ZK-STARKs do not require a ‘trusted setup,’ removing a possible weak spot.


  • Complexity: To be effective, StarkWare’s technologies necessitate a high level of technical awareness and skill.
  • Newness: Because it is a relatively new technology, it may suffer acceptance challenges and undiscovered technical concerns.

Real-world Examples

  • dYdX: StarkWare is used by dYdX, a decentralized derivatives exchange, to boost transaction capacity and speed.
  • Immutable X: Immutable X is an Ethereum Layer-2 scaling solution for NFTs that makes use of StarkWare’s technology to improve scalability.


Imagine having a Swiss army knife for Ethereum scaling and infrastructure development. Polygon, formerly known as Matic Network, is just that. It is a multi-chain scaling solution for Ethereum that supports a range of Layer-2 solutions such as Optimistic Rollups, ZK-Rollups, and others.

In simpler terms, it’s a Layer-2 ‘framework’ that allows Ethereum-compatible blockchain networks to communicate with one another.


  • Scalability: By enabling several Layer-2 solutions, Polygon significantly expands the Ethereum network’s possibilities.
  • Interoperability: Because Polygon is a multi-chain solution, it allows multiple Layer-2 chains to communicate and interact.
  • Flexibility: Within the Polygon ecosystem, developers can choose the scaling approach that best meets their needs.


  • Complexity: Managing different scaling solutions and cross-chain connections can be difficult.
  • Adoption: Because it is a relatively new and sophisticated solution, it may experience certain adoption challenges.

Real-world Examples

  • QuickSwap: QuickSwap is a decentralized exchange built on Polygon that provides rapid, low-fee transactions.
  • Aavegotchi: Aavegotchi is a DeFi-enabled crypto collectibles game developed on Polygon, using its speed and low fees.


Arbitrum is like a magical performance booster for Ethereum. It is a Layer-2 scaling solution that tries to boost Ethereum’s capacity and performance.

Arbitrum employs Optimistic Rollups technology, which allows for the majority of work to be performed off-chain while maintaining the security of the Ethereum mainnet.


  • Scalability: Arbitrum improves Ethereum’s scalability by increasing transaction speed and lowering expenses.
  • Compatibility: It is entirely compatible with Ethereum, allowing developers to port their apps without any alterations.
  • Security: Arbitrum relies on Ethereum for security, ensuring the robustness and safety of apps built on it.


  • Withdrawal Delay: Due to its Optimistic Rollups technique, there may be a substantial delay in withdrawing funds to the Ethereum mainnet.
  • Dependence on Ethereum: While it benefits from Ethereum’s security, it also inherits its congestion difficulties during peak times.

Real-world Examples

  • Uniswap: Uniswap, a decentralized exchange, has been implemented on Arbitrum to take advantage of its scalability and compatibility with Ethereum.
  • Sushiswap: Sushiswap, another decentralized exchange, is also deployed on Arbitrum with comparable purposes.

Further Reading: Ethereum Starter Kit: Smart Contract Development for Beginners


Think of Ethereum as having a turbo booster. That is what optimism is. It is a Layer-2 scaling solution meant to alleviate Ethereum’s scalability and latency difficulties.

Optimism, like Arbitrum, uses a mechanism called Optimistic Rollups, which moves most computing off-chain, enhancing transaction speed and lowering transaction costs.


  • Scalability: Optimism substantially enhances the number of transactions Ethereum can handle per second by moving computations off-chain.
  • Compatibility: It is intended to be entirely compatible with existing Ethereum contracts and tooling, making adoption simple for developers.
  • Security: Optimism, like Arbitrum, relies on the Ethereum mainnet for security, ensuring a secure environment for decentralized apps.


  • Withdrawal Delay: Optimism, like Arbitrum, uses Optimistic Rollups, which causes a delay when withdrawing funds to the Ethereum mainnet.
  • Limited Throughput: While it enhances scalability, transaction throughput remains limited when compared to other Layer-2 systems.

Real-world Examples

  • Synthetix: Synthetix, a decentralized synthetic asset platform, has partnered with Optimism to provide faster and cheaper transactions.
  • Uniswap V3: The third edition of Uniswap is also available on Optimism, providing low-fee, high-speed exchanges.

Comparative Analysis of Layer-2 Scaling Solutions

(Performance comparison: speed, cost, security)


When compared to Layer-1 blockchains, all Layer-2 systems considerably enhance transaction speed. Because of their near-instantaneous processing, State Channels and Lightning Networks are extremely efficient for micro-transactions.

Rollup-based technologies like Zero-Knowledge, Optimistic Rollups, Arbitrum, and Optimism give significant speed improvements for a broader range of applications.


Layer-2 solutions significantly cut transaction costs. Fees for the Lightning Network and State Channels are either low or non-existent. Polygon and Plasma, two rollup-based and sidechain blockchain technologies, have cheaper fees than standard Layer-1 blockchains.


In general, Layer-2 solutions retain the security of their underlying Layer-1 blockchain. Rollup-based solutions, for example, inherit Ethereum’s security.

However, some solutions, such as State Channels and Sidechains, may have extra vulnerabilities due to off-chain operations and independent security procedures.

Suitability for different types of applications

Micropayments and Payment Systems

Because of their low cost and fast speed, technologies like Lightning Networks or State Channels are ideal for applications requiring frequent, tiny transactions.

Smart Contracts and DeFi

Because of their compatibility with Ethereum and scalability, rollup-based solutions like Zero-Knowledge Rollups, Optimistic Rollups, Arbitrum, and Optimism, as well as multi-chain solutions like Polygon, are appropriate for complicated smart contracts and DeFi applications.

Explore more on DeFi: DeFi Lending: How to Earn Passive Income with Crypto

Gaming and NFTs

Polygon and Plasma, which allow scalable, low-cost transactions, may be favored for gaming applications and NFTs that demand high throughput and cheap prices.

Adoption and community support

Community Support

Because of their interoperability with Ethereum’s large developer ecosystem, Ethereum-based Layer-2 solutions like Optimism and Arbitrum have considerable community support. Polygon’s adaptability and multi-chain strategy have also piqued the curiosity of developers.


Adoption varies according to the use case and ecology. The Lightning Network for Bitcoin transactions has achieved widespread adoption. Polygon has attracted a large number of DApps in Ethereum’s ecosystem, while Optimism and Arbitrum are also gaining traction.

Future Potential and Challenges of Layer-2 Scaling Solutions

Layer-2 scaling solutions will be critical in the future of blockchain, serving as the key to unlocking the technology’s potential for broad adoption and large-scale applications.

The desire for quick, low-cost transactions will increase as more businesses and services use blockchain technology. Layer-2 solutions provide the scalability that blockchains require to compete with existing financial and IT systems, making them critical for blockchain technology’s long-term success and viability.

While Layer-2 solutions change and improve, their key function in the blockchain ecosystem remains constant: they represent the necessary bridges between blockchain technology’s promise and the practical needs of users and applications.

Anticipated developments in Layer-2 solutions


Future improvements in Layer-2 systems will almost certainly prioritize interoperability. As more Layer-2 solutions emerge, the requirement for them to seamlessly communicate and interact will become critical.

Improved User Experience

As the space matures, we may anticipate improvements in user experience, such as shorter withdrawal periods and more intuitive interfaces, making these technologies more accessible to non-blockchain enthusiasts as well as blockchain fans.

Generalized Layer-2

We may witness the emergence of “generalized Layer-2” solutions that can execute arbitrary smart contracts while retaining all of Layer-2’s scaling benefits, allowing for greater flexibility and utility.

Major challenges and potential solutions


While Layer-2 solutions show potential, convincing users and developers to embrace them remains challenging. Better developer tools and more fundamental, user-friendly interfaces can help address this.


Many Layer-2 solutions now have their distinct features and protocols, which might lead to confusion. Standardization of critical elements across Layer-2 systems could simplify and improve interoperability.


While Layer-2 solutions frequently leverage Layer-1 security, they may pose new security considerations. Continued research and peer evaluations are required to assure the security of these systems.

Partner with OnGraph for Scalable Blockchain Solutions

We discovered the huge potential of Layer-2 scaling solutions for solving the inherent scalability limits of traditional blockchains during our investigation of these technologies. Layer-2 solutions, ranging from State Channels to Rollups to Sidechains and beyond, serve as a vital link between blockchain’s revolutionary promise and its practical, real-world implementations.

As the blockchain landscape evolves, so does the demand for expert advice and technical skills. This is when OnGraph Technologies, a seasoned web and app development firm with over 15 years of experience, comes in.

OnGraph, which is led by a team of blockchain experts, assists you in navigating this complicated ecosystem, from integrating powerful Layer-2 solutions to custom blockchain creation. At OnGraph, we are dedicated to using our deep technical expertise to assist you in capitalizing on the dynamic world of blockchain.

So, why sit back and observe the blockchain revolution when you can be a part of it? Join forces with OnGraph today to build blockchain solutions that will stand the test of time.

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