How to Bridge from Ethereum Mainnet to Polygon
Celer cBridge makes it quick, easy, and secure to bridge assets like USDT, USDC, and more from Ethereum Mainnet to Polygon and from Polygon to Ethereum Mainnet by following these simple steps:
Step 1:
Connect your wallet by clicking on the “Connect Wallet” button above in order to begin your cross-chain transfer.
Step 2:
Select “Ethereum Mainnet” in the “From” dropdown menu, select “Polygon” in the “To” dropdown menu, and then select the asset type you wish to bridge to Polygon.
Please Note: You will have to switch your wallet’s network to Ethereum Mainnet in order to perform the cross-chain bridging of your selected token from Ethereum to Polygon.
Step 3:
Input the amount of the token you selected that you would like to transfer from Ethereum to Polygon in the “Send:” field. The estimated amount of that asset that is to be bridged to Polygon will be displayed in the “Receive (estimated)” field.
Step 4:
Review all of the Polygon bridge transfer information and cost estimates. If all of the cross-chain bridging transaction information is correct and acceptable, click the “Transfer” button and approve the transaction prompts to begin the cross-chain transfer.
Step 5:
Wait for your cross-chain bridge transaction to Polygon to complete. You will then receive your bridged tokens on Polygon.
Please Note: Most cross-chain transfers are completed almost instantaneously, however some may take as long as 20 minutes to complete depending on how much traffic the chain is experiencing.
If you wish to see more details about the bridge transaction from Ethereum to Polygon, you can click the links in your “Transfer History” tab.
For a more in-depth step-by-step guide on cross-chain transfers and crypto bridging see our full tutorial here:
https://cbridge-docs.celer.network/tutorial/cross-chain-transfer
Ethereum Mainnet Information
Ethereum is a decentralized blockchain platform that provides open access to digital money and data-friendly services. It is a community-built technology that is responsible for Ether (ETH) also referred to as Ethereum, as well as many different decentralized applications (dApps) that many people use today. With their tools and unique programming language, Solidity, Ethereum’s users can create, publish, monetize, and use applications on the platform, while using its Ether (ETH) cryptocurrency as payment. Ethereum allows you to move money, or make agreements, directly with someone else while serving as a decentralized public ledger for verifying and recording those transactions.
Ether / Ethereum (ETH) Current Information
Description
Ether (ETH), also referred to as Ethereum, is the main decentralized cryptocurrency used when dealing with Ethereum Mainnet and its various layer-2s like Arbitrum and Optimism. Simply put, it is the currency of when interacting with Ethereum Mainnet or its layer-2s. Whether you want to simply transfer some ETH between wallets, use ETH as collateral for creating an entirely new token, receive some bridged tokens from another chain like Polygon, or use an application someone had built on Ethereum; anytime you interact with Ethereum you will be required to pay a small fee in ETH.
Our cross-chain bridge, cBridge, supports the cross-chain bridging of Ether (ETH) 
between multiple chains with the fastest speeds, lowest costs, and most secure transactions available. The full name of this asset is Ether and the ticker of this asset is ETH.
Polygon Information
Polygon is a layer-2 network that aims to be a scaling solution that provides multiple tools to improve the speed, reduce cost, and reduce the complexity of transactions and transfers on more congested and expensive blockchains like Ethereum. As a layer-2 network, Polygon acts as an add-on layer to Ethereum that isn’t looking to change the original blockchain layer. Polygon wishes to help enable Ethereum to expand in size, security, efficiency, and usefulness. All while seeking to spur developers to bring enticing products to market. The token underpinning the network is called MATIC and is used as the unit of payment and settlement between participants who interact within Polygon.
MATIC (MATIC) Current Information
Description
MATIC is the native cryptocurrency of the Polygon network and is used to help drive development across the network and can be used for staking and paying for transaction fees. Simply put, it is the currency of Polygon and the applications running on it. Whether you want to simply transfer some MATIC between wallets, receive some bridged tokens from another chain like Ethereum Mainnet, or use an application someone had built on Polygon; anytime you interact with Polygon you will be required to pay a small fee in MATIC.
Our cross-chain bridge, cBridge, supports the cross-chain bridging of MATIC 
between multiple chains with the fastest speeds, lowest costs, and most secure transactions available. The full name of this asset is MATIC and the ticker of this asset is MATIC.
What is a Blockchain/Crypto Bridge?
Blockchain or Crypto bridges work just like the real thing, but instead of connecting physical places together, they are used to connect digital ecosystems together. These bridges can pass both information and assets between the bridged blockchains. We call this a cross-chain transfer.
As an example, if you have a need to use USDT on Polygon, and you have USDT on Ethereum Mainnet and not on Polygon, you could either deposit more USDT specifically on Polygon, or you could find a Polygon bridge that will bridge your USDT from Ethereum Mainnet to Polygon so you do not have to spend more to get additional USDT just because it is on Polygon.
There are also different types of bridging in terms of how the cross-chain transfer is done from a technical standpoint. There is liquidity-based bridging where there are liquidity pools of an asset on both the source and destination blockchains. There is also canonical-based bridging where an asset is locked on the source chain and a new asset that represents that locked asset is created on the destination chain.
Bridging and cross-chain transfers are not limited to just normal assets or fungible tokens either. Bridges can transfer and move non-fungible tokens (NFTs) between chains as well. cBridge supports 2 main models when it comes to NFT bridging, pegged NFT bridging and multi-chain native (MCN) NFT bridging. Pegged NFT bridging is similar to the canonical-based bridging mentioned above. The NFT is locked on the source chain and a new NFT that represents that locked NFT is created, or minted, on the destination chain. In the MCN NFT bridging model, however, a MCN NFT does not have the notion of “origin chain” or "original NFT". When transferring an MCN NFT from chain A to chain B, the only pattern is "Burn-and-Mint" so that there is always only one NFT across all of the chains.
Then there are the different levels of “trust” you can have in a crypto bridge. The two main types are trusted and trustless bridges. Trusted bridges depend on a central system or entity and require you to put your trust in them if you wish to use their bridge. Trustless bridges, like our own cBridge, are completely controlled by and run on automated smart contracts and algorithms that have the same security and stability as the blockchain itself.
Things start to get a more complex from there so if you are interested in learning more about the different types of bridges and the tech behind them, you can read through our documents here: https://cbridge-docs.celer.network/
What are the Benefits of Using a Blockchain/Crypto Bridge?
There are many reasons you may want to use a bridge to do a cross-chain transfer between different blockchains:
Lower transaction fees
You can take advantage of platforms with lower transaction fees and higher speeds when compared to more congested chains, like Ethereum Mainnet. Especially when exploring different decentralized applications (dApps). You can look at alternative chains, like BNB Chain, and bridge your USDC, or whatever other asset you wish to bridge, from Ethereum to BNB Chain. You can then get some of that chain’s utility token and will be able to enjoy the lower transaction fees and higher speeds afforded to chains like BNB Chain.
Take advantage of other dapps and opportunities on different blockchains
If you’ve been providing liquidity for lending out USDC on Ethereum Mainnet, but see that the interest rate for lending USDC on Polygon is significantly higher; you can use a cross-chain transfer to move your USDC from Ethereum Mainnet to Polygon in order to take advantage of that higher interest rate.
Explore other blockchain ecosystems
The Web3 world is growing fast and you now have more options than ever before when it comes to different blockchains and dApps on those chains. There are many different compelling reasons why developers are building on the chains they are and with all of this diversity it makes it difficult to select a chain to invest in. Bridges and cross-chain transfers help solve this issue. By giving you the ability to bridge assets like ETH, USDT, USDC, and BTC to different chains, this opens up your options when it comes to being able to explore alternate L1 chains and the native dapps and services that they provide.
