What mainnet and testnet networks does MetaMask support?

Main Networks Supported by MetaMask

1. Ethereum Mainnet is the primary blockchain network supported by MetaMask, allowing users to interact with decentralized applications and manage ETH and ERC-20 tokens.

2. Binance Smart Chain (BSC) Mainnet is integrated for faster and lower-cost transactions, enabling access to BEP-20 tokens and BSC-based dApps.
3. Polygon (Matic) Mainnet offers scalability solutions and reduced gas fees, widely used for DeFi and NFT platforms.
4. Avalanche C-Chain Mainnet supports high-throughput applications and enables cross-chain asset transfers within the Avalanche ecosystem.
5. Arbitrum One and Optimism are Layer 2 networks built on Ethereum, offering enhanced transaction speeds and lower costs while maintaining Ethereum's security.

Test Networks Available in MetaMask

1. Ethereum Rinkeby Testnet was previously used for testing smart contracts and dApp functionality before mainnet deployment, though it has been deprecated in favor of newer testnets.

2. Ethereum Goerli Testnet is now the recommended proof-of-stake test network for Ethereum developers, supporting contract testing and faucet-based token acquisition.
3. Sepolia Testnet provides an alternative Ethereum testing environment with active validator support and compatibility with modern tooling.
4. Mumbai Testnet serves as the test environment for Polygon, allowing developers to simulate transactions and deploy contracts before going live on Polygon Mainnet.
5. Binance Smart Chain Testnet enables developers to test dApps and smart contracts using free BNB and BEP-20 tokens in a sandboxed environment.

Adding Custom Networks in MetaMask

1. Users can manually configure custom RPC settings to connect to emerging blockchains or private networks not listed by default.

2. Each network requires specific parameters such as Network Name, RPC URL, Chain ID, Currency Symbol, and Block Explorer URL.
3. Community-driven projects often distribute their network details for integration into MetaMask to facilitate early-stage interaction.
4. Developers deploying on niche or new chains rely on this feature to validate interactions before official wallet support.
5. Caution is advised when adding unknown networks due to potential phishing risks or incorrect configurations leading to fund loss.

Frequently Asked Questions

What should I do if my MetaMask doesn’t show a specific EVM-compatible chain?Manually add the network using its RPC details. Most EVM-based chains publish these specifications on their official documentation or developer portals.

Can I use the same wallet address across different testnets?Yes, your MetaMask address remains consistent across all Ethereum-based testnets. However, each testnet operates independently, requiring separate test tokens from their respective faucets.

Is it safe to switch between mainnet and testnet in MetaMask?Switching networks is safe as long as you never send real funds to a testnet address. Always double-check the active network before confirming any transaction.

How do I get testnet tokens for development purposes?Visit the official faucet websites associated with the testnet—such as Goerli or Sepolia faucets—and connect your MetaMask wallet to receive free test ETH for development and testing.