What is multichain?

The first blockchain network, Bitcoin, was introduced in 2009 as a decentralized peer-to-peer electronic cash system, enabling users to transfer value without relying on a central authority. Ever since then, the blockchain industry has grown in leaps and bounds, with developers continuously pushing forward the capabilities of blockchain technology. An early example of this was Ethereum, which was the first blockchain to expand the concept of blockchain technology past transaction verification to a full-fledged decentralized platform. This resulted in the birth of DeFi, NFTs, and other DApps we have now that are blockchain-powered.

Now this blockchain technology system was not limited to only Bitcoin and Ethereum; hundreds of blockchains have since been created.

The Problem

A blockchain is said to be efficient and perfect when it can achieve the three trilemmas (decentralization, scalability, and security), but blockchain networks like Ethereum, Base, and Polygon can only afford to achieve two out of the three and then forfeit one. That’s just how it is. So different blockchains were all built and created to solve a problem the other is not solving. With these blockchains, the era of multi-chain began. For example: Ethereum => Security + Smart Contracts Base => Low ethereum transaction fee Solana => Speed These are a variety of blockchain networks that are solving different problems. Each chain is optimized for different things.

But a new problem appeared Now users were everywhere. Imagine this: We have 30 million users on Ethereum. We have 20 million users on Polygon. We have 10 million users on Base. Now instead of one big ecosystem, the blockchain is now fragmented, with users only able to interact on a single chain they onboarded on. Now you as a developer are missing out on 30 million users because you only deploy your smart contract on Ethereum, and the remaining 30 million users on Polygon and Base will have to switch to using Ethereum if they want to use your DApp. Most users will just give up and use another thing. This is the problem of having multiple blockchains, and that is where the concept of multichain comes in.

Where Does Multichain Come In?

As blockchain technology evolved, developers realized that no single blockchain could perfectly meet every need. While Ethereum offered strong security and decentralization, other blockchains emerged to provide faster transactions, lower fees, or better scalability. The idea is this:

Instead of pretending only one blockchain exists, design systems that can work across many blockchains.

The term "multichain" refers to an ecosystem where multiple independent blockchain networks coexist, each specializing in different areas while serving different communities of users. However, the term is used most frequently to describe applications that launch on multiple blockchains, widely known as “multi-chain applications.”

For example, instead of deploying a decentralized exchange (DEX) only on Ethereum, developers may deploy it on the following:

• Ethereum
• Base
• Polygon
• Arbitrum

This allows Ethereum users to interact with the application on Ethereum, while Base or Polygon users can use the same application on their preferred networks without the need to bridge assets or migrate to another blockchain.

Categories of Multichain Solutions

1. Multichain Applications (dApps)

A multichain application is a decentralized application that is deployed on multiple blockchain networks. For example, Uniswap is available on Ethereum, Base, Polygon, Arbitrum, and several other networks. Regardless of the blockchain you choose, you’re still using the same Uniswap platform. Think of it as the service.

2. Multichain Assets

A multichain asset is a digital asset that exists on more than one blockchain. For example, USDC is available on Ethereum, Base, Solana, Polygon, Avalanche, and many other networks. Although it exists on different blockchains, it remains the same stablecoin pegged to the US dollar. Think of it as the money.

3. Multichain Wallets

A multichain wallet is a wallet that supports multiple blockchain networks. For example, MetaMask allows users to connect to Ethereum, Base, Polygon, Arbitrum, Optimism, and other EVM-compatible networks using a single wallet interface. Think of it as your gateway to the blockchain.

Examples of Multichain

1. UNISWAP: It was originally launched on Ethereum. Uniswap later expanded to multiple blockchain networks, including Base, Polygon, Arbitrum, Optimism, and BNB Chain. Instead of requiring users to move to Ethereum, Uniswap allows them to trade tokens on the blockchain network they already use, resulting in lower fees and a better user experience.
2. OPENSEA: It was also originally launched on Ethereum as an NFT marketplace but later expanded to support additional blockchains such as Polygon, Base, and other compatible networks. This enables users to buy, sell, and mint NFTs with lower transaction fees while remaining within the same marketplace.
3. CIRCLE (USDC): USDC, issued by Circle, is available on several blockchain networks, including Ethereum, Base, Solana, Polygon, Avalanche, and Arbitrum. This allows users to send and receive the same stablecoin on different blockchains while benefiting from each network’s unique advantages.
4. Aave: Aave is a decentralized lending and borrowing protocol that operates across multiple blockchain networks, such as Ethereum, Polygon, Avalanche, Arbitrum, Optimism, and Base. Users can lend or borrow digital assets on the network that best suits their needs, whether they prioritize lower fees or Ethereum’s security.

HOW DOES MULTICHAIN WORK?

For a dApp to be a multichain and be compatible with any blockchain networks it usually have a frontend, either a website or a mobile app

myDapp.com

Then the developer deploys their smart contract on each blockchain network they want, Polygon, Ethereum, Base, and more, and gets a contract address per the deployment. When a user connects a wallet such as MetaMask, the application detects the blockchain network the user is connected to. The frontend then communicates with the smart contract deployed on that specific blockchain. If the user is connected to Base, the application interacts with the contract deployed on Base. If the user switches to Ethereum, the application automatically interacts with the Ethereum deployment instead.

                User
                  │
                  ▼
             myDapp.com
                  │
            Connect Wallet
                  │
        Detect Selected Network
                  │
      ┌───────────┼───────────┐
      ▼           ▼           ▼
 Ethereum     Base       Polygon
 Contract     Contract    Contract

Deploying the same smart contract on multiple blockchain networks does not mean those contracts automatically share data or communicate with one another. Each deployment maintains its own state and operates independently.

Benefits of Multichain

Multichain has transformed the blockchain ecosystem by allowing applications, assets, and users to operate across multiple blockchain networks.

1. Lower Transaction Fees One of the biggest advantages of multichain is the ability to choose a blockchain with lower transaction costs. For example, if gas fees on Ethereum become too expensive, users can interact with the same application on networks such as Base or Polygon, where transaction fees are significantly lower. This makes blockchain applications more affordable and accessible to a wider audience.
2. Better Scalability No single blockchain can efficiently handle every transaction from millions of users worldwide. By deploying applications across multiple blockchain networks, transaction processing is distributed rather than concentrated on one chain. This improves the overall scalability of the application and the blockchain ecosystem.
3. Reduced Network Congestion If every decentralized application operated solely on Ethereum, the network would become congested, leading to slower transactions and higher gas fees. The multichain approach distributes activity across multiple blockchain networks, reducing congestion and improving overall network performance.
4. Increased Availability and Reliability Relying on a single blockchain introduces a single point of dependency. If one network experiences congestion, downtime, or unusually high transaction fees, users can continue accessing the application through another supported blockchain. This improves the reliability and availability of the application.
5. Access to More Users Different blockchain networks have different user communities. For example:

• Ethereum has a large DeFi ecosystem.
• Solana has a strong NFT and gaming community.
• Base is rapidly growing with consumer-focused applications. By supporting multiple blockchains, developers can reach users across all of these ecosystems instead of limiting themselves to a single network.

Conclusion

Blockchain has evolved from the era of depending on a single blockchain network. As different blockchains emerged to solve different challenges, whether it is security, scalability, decentralization, speed, low cost fees, the need for a multichain ecosystem became increasingly apparent.

Rather than replacing one blockchain with another, the multichain approach embraces the strengths of multiple networks. Applications can be deployed across several blockchains, assets can exist on different networks, and wallets can provide users with seamless access to these ecosystems. This flexibility allows developers to reach a wider audience while giving users the freedom to interact with decentralized applications on the blockchain that best suits their needs.

Thank you for reading this article. I hope you now have a better understanding of what multichain is, why it exists, and how it is shaping the future of blockchain technology.