Add Network to MetaMask

WHAT IT DOES

This tool helps you add any EVM-compatible network to your MetaMask wallet. You provide the network name, RPC URL, chain ID, currency symbol, and optional block explorer URL. The tool then sends a wallet_addEthereumChain request to MetaMask, which prompts the user to confirm adding the network. It also attempts to automatically switch to the newly added network. Quick presets are included for Polygon, Arbitrum, Optimism, BNB Chain, Avalanche, and Base. All processing happens locally — nothing is sent to any server.

HOW TO USE

Connect your MetaMask wallet using the Connect button. Configure the network parameters: Network Name (e.g., "Polygon Mainnet"), RPC URL (the JSON-RPC endpoint), Chain ID (decimal, e.g., 137), Currency Symbol (e.g., "MATIC"), and optional Block Explorer URL. You can use the quick preset buttons to automatically fill in common network configurations. Click "Add Network to MetaMask" to send the request. MetaMask will display a prompt asking you to confirm adding the network. Approve the request to add the network to your wallet's network list. MetaMask will automatically attempt to switch to the new network.

TECHNICAL MECHANISM

This tool uses the MetaMask wallet_addEthereumChain RPC method, which is the standard way for dApps to request network additions. When you click "Add Network," the tool constructs a network parameters object containing the chainId (as a hex string with "0x" prefix), chainName, rpcUrls array, nativeCurrency object with name, symbol, and decimals, and optional blockExplorerUrls array. It then calls provider.send('wallet_addEthereumChain', [networkParams]) through the BGWallet bridge. MetaMask validates the request, displays a confirmation prompt to the user with the network details, and if approved, adds the network to the wallet's network list. If the network already exists, the tool falls back to wallet_switchEthereumChain to switch to it. The tool includes a preset system that pre-populates common network configurations for user convenience.

WHAT IT CANNOT SEE

This tool cannot verify if the provided RPC URL is legitimate, secure, or functional. It cannot verify if the chain ID matches the actual network — it trusts the user's input. It cannot verify if the currency symbol or other metadata is accurate. It cannot detect if the network configuration has been tampered with or if the RPC endpoint is malicious. It cannot force MetaMask to switch networks if the user denies the request. The tool cannot add networks to other wallets that do not support the wallet_addEthereumChain API, such as some mobile wallets or older MetaMask versions. It cannot validate whether the network is operational or whether the RPC endpoint returns correct data. It cannot detect if the network is a testnet or mainnet, or if it has been added previously.

PLEASE NOTE

This tool works only with EVM-compatible wallets that support the wallet_addEthereumChain RPC method (MetaMask, Trust Wallet, Coinbase Wallet, and others). The wallet_addEthereumChain API may not be available in all wallet versions or on all platforms. Always verify network configuration details from official sources before adding them. Adding a malicious RPC URL can expose your wallet to phishing or man-in-the-middle attacks. This tool is provided as a convenience utility; you are solely responsible for verifying the legitimacy of any network you add. This tool does not store or transmit any data — all processing occurs in your browser.