How to add Polygon to MetaMask?

Network Configuration Steps

1. Launch the MetaMask browser extension and click the network selector located in the top-right corner of the interface.

2. From the dropdown menu, select “Add Network” to open the manual configuration panel.

3. Input the following parameters precisely: Network Name as Polygon Mainnet, New RPC URL as https://polygon-rpc.com/, Chain ID as 137, Currency Symbol as MATIC, and Block Explorer URL as https://polygonscan.com/.

4. Verify each field for accuracy before clicking “Save” to confirm the configuration.

5. Upon successful saving, the network selector will display Polygon Mainnet as an available option.

Verification and Switching Protocol

1. After saving, click the network selector again and choose Polygon Mainnet from the list.

2. The MetaMask interface will update its header to reflect the active network; the balance section may show zero MATIC until funds are deposited.

3. Attempt a test transaction using a small amount to validate connectivity and gas estimation responsiveness.

4. If the transaction fails with “network mismatch” or “invalid chain ID”, recheck the Chain ID value—137 is non-negotiable for Polygon Mainnet.

5. Confirm that the block explorer link in the account details points to polygonscan.com, not etherscan.io or any other domain.

Risk Mitigation Practices

1. Never send MATIC tokens while connected to Ethereum Mainnet or any incompatible chain—such transfers result in permanent loss.

2. Avoid copying RPC URLs from unverified forums or third-party blogs; always source them from wiki.polygon.technology or polygon-rpc.com.

3. Disable automatic network detection features in MetaMask settings to prevent accidental switching during active sessions.

4. Manually verify the Chain ID displayed in the network details modal matches 137 before initiating any token transfer.

5. Bookmark official Polygon documentation pages for rapid reference during wallet setup or troubleshooting.

Multi-Chain Wallet Behavior

1. MetaMask stores network configurations per profile—not globally—so adding Polygon Mainnet on one device does not auto-sync to another unless cloud backup is enabled and verified.

2. When switching between Ethereum Mainnet and Polygon Mainnet, contract interaction endpoints change entirely; deployed ERC-20 addresses on Ethereum remain invalid on Polygon without bridging.

3. Gas fee displays update dynamically: MATIC-denominated fees appear only when Polygon Mainnet is selected, never in ETH units.

4. Token balances do not auto-refresh across chains; users must manually add custom tokens using their Polygon-specific contract addresses after network selection.

5. Transaction history splits by chain—no unified ledger view exists across EVM-compatible networks within standard MetaMask UI.

Common Questions and Direct Answers

Q: Can I use the same wallet address on both Ethereum and Polygon?A: Yes—the same public address works across both chains, but private key derivation remains identical while balances and transaction histories are strictly segregated.

Q: Why does my MATIC balance show zero after adding the network?A: The network addition only enables connectivity; MATIC must be transferred to your address via bridge or exchange withdrawal specifically configured for Polygon Mainnet.

Q: Is Chain ID 137 used for all Polygon environments?A: No—Mumbai Testnet uses Chain ID 80001; mainnet exclusively uses 137.

Q: What happens if I paste an incorrect RPC URL?A: MetaMask will fail to fetch block data, display “Network error”, and prevent transaction submission until corrected.