Introduction

The growing popularity of blockchain technology has necessitated the creation of numerous blockchain ecosystems. With this rising number, sharing tokens and data across different blockchain networks has been challenging. Ethereum, a popular decentralized application and smart contract blockchain, faces significant network congestion due to the increasing number of users and protocols built on the blockchain. However, some innovative projects are emerging to tackle these challenges by building bridges that can decongest certain chains and facilitate asset transfers between networks.

Polygon is among the leading projects redefining blockchain bridging. Polygon Bridge is designed to increase interoperability between the Polygon and Ethereum blockchains. With a compatible cryptocurrency wallet, users can quickly transfer assets back and forth across different networks. This article provides a step-by-step guide on using the Polygon Bridge to move tokens from Ethereum to Polygon and vice versa.

Understanding Polygon Bridge

Polygon is a layer 2 framework for creating Ethereum-compatible blockchain networks and scaling solutions. It aims to enrich the Ethereum ecosystem by providing tools to build scalable decentralized applications (dApps) and increase Ethereum’s transaction throughput with lower fees. SushiSwap, Aave, and Curve are some of the DeFi platforms utilizing the advantages of the Polygon Network.

Polygon Bridge is a cross-chain interoperability channel assisting interchain communication between different blockchains to Ethereum and vice versa. One of Polygon Bridge’s unique features is its fast transactions. While the Ethereum network can handle 14 transactions per second (TPS), the Polygon Bridge facilitates up to 65,000 TPS. This provides resources for processing cheaper and faster cross-chain transactions. Additionally, Polygon Bridge supports the transfer of diverse digital assets, including ETH, ERC-20, ERC-1155, ERC-777, and ERC-721 tokens

How Polygon Bridge Works

The Polygon Bridge uses a dual-consensus architecture to optimize speed and decentralization. It features significant improvements over other blockchain bridges, with its UX improvements and fast finality. It also supports arbitrary state transitions on sidechains with tokens compatible with the Ethereum Virtual Machine (EVM).

When tokens are bridged over the Polygon Bridge, there will be no change to the token’s circulating supply, which means the token will remain in circulation. Tokens that leave the Ethereum network are locked, and the same number of tokens will be minted on the Polygon network on a 1:1 basis as the pegged tokens. When the tokens are transferred back to Ethereum, the pegged tokens on Polygon will be burnt, and the tokens on Ethereum will become unlocked.

Currently, users can bridge on Polygon via the Proof of Stake (PoS) and the Polygon zkEVM mechanisms. Although users can choose which bridge they prefer, the PoS bridge is recommended for most users because it is fast and supports ETH and most ERC tokens. On the other hand, Polygon zkEVM may also be used as it supports popular assets, including ERC-20 and ERC-777 tokens, and does not require mapping before bridging tokens.

Why Use Polygon Bridge for Cross-Chain Transactions?

The popularity of Ethereum has caused significant network congestion and high gas fees due to its substantial volume of transactions. The Polygon sidechain provides a layer-2 scaling solution for Ethereum transactions, making accessing the network and transferring crypto assets between platforms easier, faster, and cheaper.

The Polygon Bridge is arguably the most important technological part of the Polygon ecosystem. It provides a bridge through which ERC tokens and NFTs can move freely between Polygon and Ethereum.

Therefore, the Polygon Bridge is handy when the movement of tokens between Polygon and Ethereum is required. This is especially useful for users using a dApp that runs on Polygon, such as QuickSwap. Or users that want to transfer NFTs between different chains, but high gas fees on Ethereum are making that prohibitively expensive.

Polygon Bridge allows for utilizing diverse dApps and accessing various financial services on the Ethereum and Polygon chains. It can enable users to avoid high gas fees and access a world of dApps and play-to-earn applications. Apps like Aavegotchi, Neon District, and Terra Virtua Kolect have slowly migrated to Polygon because of these advantages.

What You Need to Bridge With Polygon

To utilize Polygon Bridge, you need to have the following:

• A compatible crypto wallet: Polygon Bridge supports Metamask and other wallets like Gate.io Web3 wallet and Phantom.
• Some ETH and MATIC tokens: Users need these coins to pay for gas fees while bridging or utilizing dApps.
• A Polygon bridge address: This smart contract address allows users to transfer assets between Ethereum and Polygon.

To get started, you need to connect your crypto wallet (Metamask, for instance) to the Polygon network. To do this, go through these steps:

1. Install Metamask in your Chrome browser.

Source: Chrome Web Store

1. Click “Add to Chrome’’. After the installation is successful, you can create an account.

Source: Metamask

1. To create an account, you can choose “Import Wallet” or “Create Wallet”. Here, we choose to “Create Wallet”.

1. Create a password and back up your mnemonic phrases. This is very important to recover your wallet in the future.

1. After completing the mnemonic phrases verification, the account is successfully created. Then, you can connect to the Polygon network by clicking “Connect Wallet”.

Source: Polygon Network

1. Next, you will be asked to sign a message to connect your MetaMask wallet to the Polygon network. Cross-check the information and click “Connect” to proceed.
   

Source: Metamask

Once done, you can conveniently go through the process to bridge your tokens. The following section provides a guide on bridging tokens via the Polygon POS Bridge.

How to Bridge Tokens Via Polygon POS

Users can bridge their token from Ethereum to Polygon and vice versa via the PoS Bridge. Let’s go through the step-by-step process:

From Ethereum to Polygon

1. After connecting your Metamask to the Polygon network, Click the “Bridge” button on the left to transfer assets from the Ethereum mainnet to Polygon.

Source: Polygon Network

1. Select a token to use for the bridge by clicking on its name. After entering the desired amount, click the “Bridge ETH to Polygon POS” button.

1. You will be asked to sign the bridge transaction on your wallet. Carefully review all the transaction details, including the tokens and estimated cost, before clicking “Confirm”.

Source: Metamask

1. Once confirmed, wait for the tokens to arrive in your wallet.

From Polygon to Ethereum

You will follow almost the same process to bridge funds from Polygon back to Ethereum.

1. Click the arrow button to reverse the bridge from “Polygon to Ethereum”.

Source: Polygon Network

1. Select the asset and amount you want to bridge. After entering the desired details, click the “Bridge Polygon POS to ETH” button.
2. Review the transaction details and projected gas fees. If everything is fine with you, click “Continue.” Then, proceed to sign and approve the transfer to your wallet.

1. The bridge progress and estimated time will appear on your screen as shown below:

1. Click “Claim” to transfer the assets to your MetaMask wallet. Then, log into your wallet and click “Import Tokens”.

How to Bridge Tokens Via Polygon zkEVM

Users may alternatively opt for bridging their assets via Polygon zkEVM, a ZK-rollup scaling solution. The steps are very similar to the process involved in bridging through Polygon POS.

From Ethereum to Polygon

1. After connecting your Metamask to the Polygon network, Click the “Bridge” button on the left.

Source: Polygon Network

1. The platform chooses Polygon POS by default, so you must change the bridge to Polygon zkEVM.

1. Select a token to use for the bridge by clicking on its name. After entering the desired amount, click the “Bridge ETH to Polygon zkEVM” button.

1. You will be asked to sign the bridge transaction on your wallet. Carefully review the transaction details, including the tokens and estimated cost, before clicking “Confirm”.

1. Once confirmed, wait for the tokens to arrive in your wallet.

From Polygon to Ethereum

To bridge funds from Polygon zkEVM back to Ethereum, go through these steps:

1. Click the arrow button to reverse the bridge to “Polygon to Ethereum.”

1. Select the asset and amount you want to bridge. After entering the desired details, click the “Bridge Polygon zkEVM to ETH” button.
2. Review the transaction details and projected gas fees. If everything is okay, click “Continue”. Then, sign and approve the transfer to your wallet by clicking the “Confirm” button.
3. The bridge progress and estimated time will appear as shown below:

1. Click “Claim” to transfer the assets to your MetaMask wallet. Then, log into the wallet and click “Import Tokens”.

How to Bridge Tokens Via Third-Party Bridges

Users can explore third-party bridges if they don’t want to wait too long to bridge assets via the native Polygon bridge. This feature allows for the bridging of tokens from other blockchains, including Ethereum, Avalanche, BNB Chain, Optimism, and Arbitrum, to Polygon.

1. Click “Bridge using Third-Party Bridges”.

Source: Polygon Network

1. Select a third-party bridge from the list that supports the token you want to bridge.

Note that different bridges support different assets and have different fees. You can choose a bridge depending on the chain your asset is compatible with.

How to Bridge Tokens Via Gate.io

As a leading crypto exchange, Gate.io can also bridge assets for users to enjoy the benefits of different blockchain networks. This is because the platform supports thousands of cryptocurrencies and enables the conversion of digital assets quickly and easily without charging recurring fees.

To do this, go to the Gate.io crypto exchange website and create a Gate.io account if you don’t have one. Fund your spot trading account, and go through the steps to buy some tokens. Let’s say you bought some ETH and wish to bridge it to Polygon (MATIC). Go through the following steps:

1. Go to the Gate.io Convert Page to convert the ETH tokens to USDT. USDT is a stablecoin that can be exchanged for most tokens on the exchange platform.

Source: Gate.io

1. After successfully converting the desired amount of ETH to USDT, convert the acquired USDT to MATIC.

1. Upon completion, you are ready to explore the world of the Polygon network by sending the acquired MATIC to a compatible web3 wallet, for instance, Metamask.

Using Blockchain Bridges: Challenges and Future Outlook

Despite the importance of blockchain bridges as an inter-chain communication enabler, there are challenges associated with using them.

Challenges

Since bridges work based on the principle of cross-chain interoperability, security flaws may expose bridged assets to risks. These include network intrusion or smart contract compromise, potentially leading to transaction delays or loss of assets. Also, the evolving nature of blockchain technology and regulatory uncertainties may impact the functionality of certain cross-chain bridges.

Some bridges may face a liquidity crisis, making it difficult to move large assets around. Moreover, different bridges may have different transaction speeds and costs. When conducting cross-chain transactions, users must be cautious, recognize inherent risks, and take appropriate precautions before interacting with the platforms.

Future outlook

With the growing demand for interoperability among blockchain networks, the need for blockchain bridges increases. As blockchain technology becomes more mainstream, cross-chain bridges will be essential in promoting cooperation among DeFi applications and improving users’ opportunities to engage across multiple blockchains easily.

The future of blockchain bridges appears promising, poised for evolution and integration across diverse blockchain ecosystems. Polygon, for instance, is constantly innovating and adding new features, like the Polygon zkEVM, and including more third-party bridges. Improvements in interoperability, smooth asset transfers, and network friction reduction are expected to be the main focus areas.

Conclusion

Using Polygon Bridge to transfer tokens to and from Polygon is relatively easy. The Polygon Bridge’s interoperability allows users to transfer their assets between Ethereum, Polygon, and other blockchains. It offers an alternative for users looking to experience the DeFi platforms and dApps available on the Polygon network. As Polygon constantly innovates to connect different blockchains into an interconnected whole, the future of blockchain interoperability is auspicious.