By: Peter

Ethereum L2 chains offer faster and cheaper transactions than Ethereum L1.

You could save thousands of dollars in transaction fees by learning crypto using Layer 2 and alternative Layer 1 chains instead of the main Ethereum blockchain. 

In this guide, we’ll cover:

1. What are L2 chains?
2. What is Polygon?
3. How to go from fiat to Polygon?
4. How to bridge to Polygon?

What follows is not investment advice.

What are L2 chains?

Let’s start with a few definitions:

1. Layer 1 chain is the main Ethereum blockchain. Other non-ETH L1 chains include Solana, Avalanche, and Terra.
2. Layer 2 chain process transactions off-chain before bundling and submitting them to Ethereum L1. Examples include Arbitrum, Optimism, and Loopring. 
3. Sidechains are separate blockchains with their own gas token. Polygon is the most popular sidechain.

L2 chains and sidechains offer faster and cheaper transactions than Ethereum L1. We highly recommend using these chains to do transactions.

To illustrate how these chains work, we’ll do a deep dive on Polygon for the rest of his guide.

What is Polygon?

Polygon is an Ethereum L2 scaling solution co-founded in 2017 by Jaynti (white paper). Polygon’s main product is a sidechain compatible with Ethereum with MATIC as its native token. Recently, the protocol raised $450M to invest in a full suite of Ethereum scaling solutions.

Polygon has 7,000+ dapps in its ecosystem, making it the most mature out of all Ethereum scaling solutions.

To get started with Polygon:

1. Add Polygon to your Ethereum wallet: For Metamask, visit Polygonscan and tap “Add Polygon Network” on the bottom right.
2. Get some Polygon ETH and MATIC: You need Polygon ETH and MATIC (native gas token) to use Polygon. You can get both tokens directly from fiat (e.g., US dollar) or through an ETH bridge. We cover both paths below.
3. Browse Polygon NFTs or dapps: Browse Polygon NFTs on OpenSea or check out Polygon’s dapp ecosystem.

How to move fiat to Polygon?

You can buy Polygon ETH and MATIC with your credit card using platforms like Moonpay, Sendwyre, and crypto.com. If you want to buy a Polygon NFT for example, you can tap “Buy with card” on OpenSea directly. Note that you need to verify your personal information firs (e.g., upload a driver’s license) to move fiat to Polygon.

How to bridge ETH to Polygon?

Bridging is just a fancy word for transferring ETH from Ethereum L1 to the Polygon sidechain. You need to pay a one-time gas fee (e.g., $60-100) to move your ETH from Ethereum L1 to Polygon. 

You can use OpenSea to bridge ETH to Polygon as follows:

1. Make sure you have some ETH in your wallet.
2. Visit OpenSea and tap on the wallet icon to connect your wallet.
3. Tap on the wallet icon again, tap “more” next to your ETH, and select “Bridge to Polygon”

4. Choose how much ETH you want to bridge in the pop-up and tap “Convert tokens.” Sign the transaction in your wallet by paying ETH gas (see our guide on "How to pay less gas?"). 

5. The bridging process usually takes 5-10 minutes. Once successful, you should see Polygon ETH show up in your wallet.

You also need some MATIC to pay for gas on Polygon. To get MATIC:

1. Make sure you bridged some ETH to Polygon ETH successfully. 
2. Visit Polygon wallet and tap Swap for gas token on the left nav.
3. Select 1 MATIC or a custom amount and tap Approve.
   

As you can see, it’s simpler and cheaper to get Polygon ETH and MATIC from fiat directly than to bridge.

Now that we covered Ethereum L2, let's talk about how you can save gas by using non-ETH L1 chains like Solana, Avalanche, and Terra.

Up next: How to use other L1 chains?

Learn more

• NFT learning path (Odyssey)
• Layer 2 roll-ups (Ethereum Foundation)‍
• Fiat onramps (Polygon)