How do L2s work? Are they secure?

Each L2 is different. Their common goal is to save space, time and fees on the main Ethereum chain by compressing and batching transactions before sending them to it for final validation. Different L2s use different cryptographic algorithms to do this. Their security relies on their cryptographic algorithms as well as the security of the main Ethereum chain.

Which L2 networks can I use to send grant funds to Gitcoin?

Gitcoin.co currently supports Polygon and ZKSync.

How do I use an L2 network to fund projects on Gitcoin?

Since L2 networks are layers on top of the main Ethereum network, you manage your funds on them much like you manage your funds on Ethereum.

First, you will need to have a wallet to manage your funds on the L2 that you choose. Next, you will need to get funds into that wallet. Then you will be able to choose that L2 during the checkout process on Gitcoin.

How do I set up a wallet on an L2 network?

Good news! If you already have an Ethereum address, you already own the same address on both Polygon and ZKsync.

If you do not already have a preferred cryptocurrency wallet we recommend you do research before choosing one. There are many factors that go into choosing wallet software and hardware, including security and ease-of-use, that are beyond the scope of this guide.

To use the Polygon network you will need to have a crypto wallet that supports it. MetaMask is one commonly-used wallet that supports Polygon. If you are using MetaMask you will need to add the Polygon servers to it so it can use them.

To use ZKSync, once you have either MetaMask or a wallet that supports WalletConnect installed, go to https://wallet.zksync.io/account to claim your address.

Which L2 should I use when donating to Gitcoin Grants?

Polygon and ZKSync differ in their transaction fees and the ways there are to transfer funds into them.

If you already have funds on one of our supported L2 networks, you should use that. If not, the table below contains a brief comparison of our supported L2s’ transaction fees and supported funding methods. Many exchanges support withdrawing funds directly to them, bypassing Ethereum transaction fees entirely.

Bridging (transferring) funds from mainnet Ethereum to an L2 is also possible, but in many cases this may be the least cost-effective method. Bridging funds from Ethereum to an L2 requires paying full Ethereum transaction fees to use the smart contracts on the bridge. If you already have funds on Ethereum and are sending over a large amount of funds at once this may still be a cost-effective method for you. Always check your estimated fees (“gas”) before submitting any transactions.

Comparison of our supported L2s and ways to fund:

L2	TRANSACTION FEE INFORMATION	WAYS TO FUND
Polygon	Polygon Gas Tracker (1 Matic GWEI = 0.000000001 MATIC)	Withdraw from a supported exchange, including Binance.com (not Binance.US), Crypto.com, Kucoin, OKX, and Okcoin * you are responsible for doing your due diligence on any exchanges you use * see your exchange’s Help Center for details on how to withdraw to PolygonBuy on ramp.network or Bridge from Ethereum (must pay full Ethereum transaction fees for using bridge)
ZKSync	Transaction cost information	Buy on ramp.network or Bridge from Ethereum (must pay full Ethereum transaction fees for using bridge)

How do I see my funds on Polygon?

If you are using MetaMask wallet, open the MetaMask window and use the menu at the top to change to the Polygon Mainnet network:

If you are using a different wallet, please see its documentation for help on how to configure it to use Polygon and how to switch its active network to Polygon.

How do I see my funds on ZKSync?

Go to https://wallet.zksync.io/ and connect your L1 wallet to see your ZKSync account.

How do I fund grants on Gitcoin using funds from a supported L2?

First, find some grants you want to support!

Go to https://gitcoin.co/grants/explorer/ and browse the available grants. Once you find one that seems interesting, click on it to view more information about it. Make a donation by clicking the Add to Cart button on the right.

Once you’ve got all the grants in your cart that you want to support, click the cart icon at the top of your screen to check out:

On the checkout page you can choose how much you want to contribute to each grant. Grants are denominated in DAI, a stablecoin pegged to 1 USD.

When you’re ready, click the dropdown arrow on the “I’m Ready to Checkout” button to choose which network you want to send your funds from:

You will complete the checkout process using either your Polygon wallet or ZKSync Checkout.

And that’s it! You just saved time and money by using an L2 network to donate to Gitcoin Grants!

Wait! I have funds left over! How do I get my funds off of an L2?

In general, the methods that can be used to get funds onto an L2 network can also be used to get funds off of one. Most exchanges (see table above) that support withdrawing to an L2 will also support receiving deposits from it, and the bridges for both Polygon and ZKSync support sending funds to and from Ethereum mainnet. Please note that if you bought directly using ramp.network you will need to bridge back to mainnet or send the funds to a supported exchange, as ramp.network does not currently support withdrawals.

Congrats, and thank you for donating to Gitcoin Grants! We couldn’t do this without you!

– Team Gitcoin

This post is one of the winning submissions from the Schelling Point Hackathon. bounty: (Blogpost To Explain How To Bridge To Layer 2’S) Thanks to william-weber and lukerhoads

If you have an idea for a blogpost or would like to help us create helpful content like this, join Gitcoin’s Discord and DM me at Jonas | Gitcoin#8327.