How to Set Up MetaMask on Layer 2 and Cut Ethereum Gas Fees

Ethereum mainnet has limited space in each block, so when demand rises, users bid against each other and gas prices climb. Layer 2 networks, mostly rollups, move transaction execution off mainnet. They then post compressed transaction data back to Ethereum, which is what lets Ethereum act as the settlement and security layer.

The saving comes from sharing. A rollup bundles many user transactions into batches, and the cost of posting a batch to Ethereum is split across everyone in it. Your transaction pays for its own computation on the layer 2 plus a small share of that Ethereum data cost.

What this means in practice

• Swaps, transfers and approvals on a layer 2 usually cost far less than the same action on mainnet.
• Fees are not fixed. They rise when the layer 2 is busy or when Ethereum data costs rise.
• You still pay something, and you still need the right gas token in your wallet.
• Moving funds between Ethereum and a layer 2 uses a bridge, and the Ethereum side of that move is charged at mainnet gas rates.

Two families are worth knowing. Optimistic rollups, such as Arbitrum One, OP Mainnet and Base, assume transactions are valid unless challenged. Zero-knowledge rollups, such as Linea and Scroll, post validity proofs. The difference matters mostly for withdrawal times back to Ethereum, covered later.

MetaMask works with all of these because they are EVM-compatible. The wallet does not change. You add a network, fund it, and the same account address works there.

Preparation takes a few minutes and prevents most beginner mistakes.

Checklist

1. A genuine MetaMask install. Get the browser extension or mobile app only from the official MetaMask website or your browser's or phone's official store listing. Check the publisher name. Fake extensions and cloned apps are a common way people lose funds.
2. A backed-up Secret Recovery Phrase. MetaMask shows a 12-word phrase when you create a wallet. Write it on paper or metal and store it offline. Never type it into a website, a chat or a support form. Real MetaMask support will not ask for it.
3. A strong wallet password. This protects the local copy on your device. It does not replace the recovery phrase.
4. Some ETH on Ethereum mainnet, or a withdrawal route from an exchange. You need funds to bridge. If you hold ETH on a centralized exchange, many let you withdraw directly to a layer 2 network, which can skip the mainnet fee entirely. Pick the network carefully at withdrawal.
5. A small test amount in mind. Plan to send a small first transfer to confirm everything lands where expected before moving the full amount.
6. A clear goal. Decide what you want to do on the layer 2, such as swapping, lending or minting, because that decides which network suits you.

If you hold significant value, consider connecting a hardware wallet to MetaMask. It keeps the signing keys off your computer, and the same layer 2 setup steps apply.

Choose by what you want to use, not by fee headlines. The apps you need must be live on the network, and your funds should be easy to move in and out.

Network	Type	Chain ID	Gas token
Arbitrum One	Optimistic rollup	42161	ETH
OP Mainnet	Optimistic rollup	10	ETH
Base	Optimistic rollup (OP Stack)	8453	ETH
Linea	zk rollup	59144	ETH
Scroll	zk rollup	534352	ETH
Mantle	Layer 2 network	5000	MNT
Polygon PoS	Separate proof-of-stake chain	137	POL

Polygon PoS is often grouped with layer 2s but runs its own validator set rather than being a rollup, so its security model differs. Treat it as a separate choice.

How to decide

• Start with the app. Open the app you want and see which networks it supports.
• Check liquidity. Larger networks usually have deeper markets for swaps.
• Check the gas token. Networks that use ETH are simplest if you already hold ETH. Mantle needs MNT.
• Check bridging options. Each of these has an official bridge, such as Arbitrum Bridge, Optimism Bridge, Base Bridge, Linea Bridge, Scroll Bridge, Mantle Bridge and Polygon Bridge.

Chain IDs rarely change, but confirm them against the network's official documentation when you add it. Sites that rank networks by activity or fees change daily, so look at a live dashboard rather than relying on any published ranking.

MetaMask includes several popular networks, and menus change between versions, so the labels below may differ slightly.

Option 1: pick from the built-in list

1. Unlock MetaMask and click the network selector at the top of the window.
2. Find the network in the list. If it is not shown, look for an option to show or add more networks.
3. Select it. MetaMask switches, and your balance on that network appears, probably zero at first.

Option 2: add a network manually

1. Open the network selector and choose the option to add a network, then add a custom network.
2. Fill in the fields from the network's official documentation: network name, default RPC URL, chain ID, currency symbol and block explorer URL.
3. Save, then switch to the network.

Option 3: approve a request from a dApp

Many apps prompt MetaMask to add their network. Read the popup. The chain ID and name should match what you expect, and you should have opened the app from a bookmark or the official site.

Checks after adding

• The chain ID shown in the network details matches the table in this guide or the official docs.
• The currency symbol is correct. A wrong symbol is harmless to funds but signals you copied the wrong settings.
• The block explorer opens the right site for that network.

The RPC URL is the server MetaMask uses to read the chain and submit your transactions. A malicious RPC can show false balances or pull you into scams, so use only RPC details from official documentation, never from a social media reply or an unknown listing.

Funds reach a layer 2 in one of three ways. Each has different cost and risk.

1. The canonical bridge

The canonical bridge is the official route run by the layer 2's team: Arbitrum Bridge, Optimism Bridge, Base Bridge, Linea Bridge, Scroll Bridge and others. Steps are broadly similar:

1. Confirm the bridge address from the network's official documentation and bookmark it.
2. Connect MetaMask while it is on Ethereum mainnet.
3. Choose the asset and a small test amount.
4. Review the mainnet gas estimate in the MetaMask confirmation, then approve.
5. Wait for the deposit to arrive, usually minutes, and switch MetaMask to the layer 2 to see it.
6. Repeat with the remaining amount.

The mainnet gas fee is the main cost of a deposit, so bridge once in a larger amount, not many small ones.

2. A third-party bridge or aggregator

Services such as Across, deBridge and Symbiosis route funds between many chains, often quickly, and can start from another chain instead of mainnet. They use their own contracts and liquidity, so they add smart contract risk. Compare the quoted fee, the expected arrival time and the received amount before approving.

3. Exchange withdrawal

Many centralized exchanges let you withdraw ETH or stablecoins directly to a layer 2 address. This can avoid mainnet gas entirely. Select the correct network in the withdrawal form, paste your MetaMask address, and send a small test first. Withdrawal fees and supported networks are set by the exchange, so check the form.

Never approve a bridge from a link sent to you in a message. Open it from your own bookmark.

Once funds are on a layer 2, the work is mostly about spotting costs before you confirm.

Reading the MetaMask confirmation

The confirmation window shows an estimated network fee in the gas token, usually with a fiat equivalent. On a layer 2 this single figure covers both the layer 2 execution and the Ethereum data portion, so you do not pay for them separately.

MetaMask offers fee options such as low, market and aggressive, and an advanced editor. On most layer 2s, the default market setting is fine. Raising it rarely matters, and lowering it can leave a transaction waiting.

Habits that keep fees down

• Stay on the layer 2. Every trip to mainnet carries mainnet gas. Do your swaps, lending and minting where the funds already are.
• Bridge in bulk. One larger deposit costs less than several small ones.
• Skip repeated approvals. Approve exactly what you need, but avoid approving the same token over and over by planning your activity.
• Batch actions where an app allows it. Some apps combine steps into one transaction.
• Check congestion. Block explorers for each network show current gas prices. Use them rather than guessing.
• Compare routes. Aggregators show multiple paths, and the cheapest quoted route can differ by network and time of day.

The fee for simple transfers is usually lower than for swaps or contract-heavy actions. If a fee seems far above normal, cancel and look at the explorer before retrying. Quoted fees are live figures that change often, so this guide gives none. Use the network's explorer or your wallet's estimate.

Going back to Ethereum is where layer 2 users often get surprised.

Optimistic rollups

Arbitrum One, OP Mainnet and Base use a challenge window so that invalid transactions can be disputed. Withdrawals through the canonical bridge generally require waiting about a week before you can finalize on Ethereum, and the final claim step costs mainnet gas. The exact period is set by each network, so read the bridge page before starting.

Zero-knowledge rollups

Linea and Scroll rely on validity proofs, and their withdrawal timing depends on proof and finalization processes. It can be shorter than optimistic rollups, but it varies by network and changes over time, so check the current bridge notes.

Faster exits

• Third-party bridges such as Across or deBridge can deliver funds on Ethereum or another chain much faster, because liquidity providers front the funds. You pay a fee and take on additional contract risk.
• Exchange deposits. Some exchanges accept deposits directly on layer 2 networks, so you can sell or move without touching mainnet. Choose the correct network on the deposit page.

Planning ahead

1. Decide whether you need to return to mainnet at all. Many users never do.
2. If you do, compare the canonical route, a fast bridge and an exchange route for cost and time.
3. Keep enough gas token on the destination side for follow-up steps.
4. Withdraw a small amount first if the route is new to you.

A cheap deposit does not mean a cheap exit, so factor the return trip into your decision before moving large amounts.

Layer 2 networks use the same wallet, so the same threats apply, plus a few that come from adding networks and bridges.

Network and RPC safety

• Add networks only from official documentation or from MetaMask's own list.
• Verify the chain ID and symbol after adding.
• Do not paste RPC details given to you in a message, reply or pop-up on an unfamiliar site.

Bridge and site safety

• Bookmark each bridge and app after finding it from official documentation.
• Treat ads and public reporting above the real site with suspicion. Fake bridge sites copy official designs.
• Read what you sign. A bridge deposit should not ask to approve unlimited spending of unrelated tokens.

Approvals

• Token approvals persist after a transaction. Review them from time to time with a reputable approval-checking tool and revoke ones you no longer use. Revoking costs a small gas fee on that network.
• Where an app lets you set a spending cap, choose a limit that fits the action.

Keys and devices

• Never share your Secret Recovery Phrase or private key. No bridge, airdrop or support agent needs it.
• Consider a hardware wallet for larger balances.
• Use a separate MetaMask account for experiments, and keep your main funds elsewhere.

Address caution

Your regular account address works on every EVM network, but some smart contract wallets and exchange deposit addresses do not exist on every chain. Sending to one on the wrong network can mean lost funds. Confirm the address works on the network you chose, and send a test amount first.

Unsolicited tokens that appear in your wallet are often scam bait. Do not interact with them or their websites.

Most problems have simple causes.

Balance does not show

• Check that MetaMask is on the right network.
• Confirm the transaction on the block explorer for that network. If it succeeded, the funds are there.
• Import the token manually using the contract address from the token's official page if it is not listed.

Insufficient funds for gas

You hold tokens but no gas token on that network. Bridge or withdraw a small amount of the gas token (ETH on most of the networks above, MNT on Mantle, POL on Polygon PoS). Always keep a small reserve.

Transaction pending or stuck

• Wait a few minutes, since some bridges and networks take time.
• If MetaMask shows a speed-up or cancel option and the transaction has not been included, you can use it, which costs additional gas.
• Do not resubmit repeatedly, which can create duplicates.

Deposit has not arrived

Canonical bridges show deposit status on their own page. Check there and in the explorer for both networks before contacting support. Contact only through official channels, and ignore anyone who messages you first offering help.

RPC errors or slow loading

The default RPC may be overloaded. MetaMask lets you pick or add another RPC for a network, but only use one published in official documentation.

Sent to the wrong network

Switch to the network where you sent, since the funds may be at your address there. If you sent to an exchange or contract, recovery depends on that service. Contact their official support promptly with the transaction hash.

Saving the transaction hash of every bridge step makes support requests faster.