Course Content
How to Use the Polygon Bridge?
The Polygon Bridge allows users to quickly transfer ERC tokens and NFTs to the Polygon sidechain. There are primarily two bridges on Polygon, the Proof of Stake (PoS) Bridge and the Plasma Bridge. Both can bridge assets from Ethereum to Polygon (and vice versa), but they adopt different security methods. The PoS Bridge uses the Proof of Stake (PoS) consensus algorithm to secure its network. It supports the transfer of Ether (ETH) and most ERC tokens. It’s the recommended option for most users. The Plasma Bridge is for devs that need increased security. It uses the Ethereum Plasma scaling solution and supports the transfer of MATIC, ETH, ERC-20, and ERC-721 tokens.
How to Use the Polygon Bridge?
About Lesson

If you wish to transfer MATIC or other Polygon tokens to Ethereum, you can do it via the Plasma Bridge. Note that the Plasma Bridge only supports the transfer of ERC-20 and ERC-721 tokens, which include ETH and MATIC.

In this example, we’ll transfer MATIC tokens from Polygon to Ethereum using MetaMask. By default, the MetaMask wallet is only connected to the Ethereum mainnet. You need to add the Polygon network to your wallet before you can view your MATIC and start the process.

Step 1: Adding Polygon to MetaMask

There are two methods to add the Polygon network to your MetaMask wallet. The default method is to add it manually (see How to Add Polygon to MetaMask). However, you can also use the Polygon Wallet interface to quickly add Polygon to the network list of your MetaMask.

1. To do so, click the [Switch to Polygon] button on the top. Make sure that you’ve already connected your MetaMask wallet.

2. You’ll see a pop-up from your MetaMask extension with the Polygon network details. Click [Approve].

3. Done. The Polygon network has been added to your MetaMask. Now, you need to switch your MetaMask from the Ethereum Mainnet to the Polygon network. You can do so by clicking [Switch network].

4. You can now see MATIC in your MetaMask wallet.

Step 2: Bridging MATIC to Ethereum using MetaMask

1. Go to the [Bridge] interface and click [Withdrawal]. Choose [Matic Token] from the token list, enter the amount and click [Transfer].

The system will automatically select [Plasma Bridge] for the transfer mode.

2. Read the important notes and click [Continue] when you are ready.

3. You’ll also see the estimated gas fee for this transaction. If you are ok with the gas costs, click [Continue] to proceed. 

4. Review your transaction details before clicking [Continue].

5. A MetaMask pop-up will appear for you to confirm the transaction. Click [Confirm], and you’ll see the transfer in progress.

You need to manually confirm three transactions for a Plasma Bridge transfer. The first one is to initiate your withdrawal from the Polygon wallet, which could take up to 3 hours.

6. Once the checkpoint arrives, it means that your transaction is validated on the Ethereum blockchain. You need to confirm a second transaction to start the challenge period. This is a measure to offer increased security for withdrawal transactions.

7. After the challenge period, all you need to do is click [Continue] to send the MATIC tokens to your MetaMask wallet.