The Site Asked You to Add a Network. MetaMask Does Not Verify It.
A website can ask MetaMask to add a custom network. MetaMask shows the site's details and does not verify them. Check the RPC and chain ID, or reject the prompt.
The Site Asked You to Add a Network. MetaMask Does Not Verify It.
A website can ask MetaMask to add a custom network. The confirmation lists details the site provided. MetaMask's verifying-custom-network page says it does not verify custom networks.
RPC stands for remote procedure call, the method a wallet uses to talk to a blockchain. A chain ID is the number MetaMask uses when it signs transactions for that network.
This is educational coverage of MetaMask help pages. It is not a recommendation to add any network.
What MetaMask Shows You
When a website requests a custom network, MetaMask displays the network name, network URL, chain ID, currency symbol, and an optional block explorer URL. Those fields come from the website.
MetaMask performs some basic validation. It can warn if something looks unusual, and it will not add the same network twice. Even if those checks pass, the network can still be malicious or misrepresented. Trust the details only as much as you trust the website.
What a Malicious Network Can Do
MetaMask's custom-networks guide says not all networks are safe. Custom networks often have different security and reliability than Ethereum mainnet.
A malicious network provider can lie about the state of the blockchain, withhold transactions, and record your network activity and IP address.
Your address can look the same on more than one chain. The assets and transactions do not. Sending tokens directly from one network to another can cause permanent loss. MetaMask says to use an established bridge or portal instead. Gas is paid in that network's native token, not in ETH unless you are on Ethereum.
How to Check Before You Approve
MetaMask lists some networks as pre-enabled. Others sit under Additional networks and can be added from that list. Prefer a network already in MetaMask when it is the one you need.
If a website still asks you to add a network, open See details. Compare the name, RPC URL, chain ID, currency symbol, and explorer URL with the network's own documentation. If you are unsure, reject the request.
MetaMask points to Chainlist at chainid.network as another way to add networks. The same help page says MetaMask does not maintain the network information on Chainlist. Check the details before you confirm.
Adding a custom RPC URL to Ethereum, Linea, Base, Arbitrum, or BNB Smart Chain disables Smart Transaction features such as MEV protection until you switch back to the default RPC. A network added on the browser extension does not appear on MetaMask Mobile, and the reverse is also true.
What This Article Does Not Confirm
CryptoWorkPro did not test a named RPC, chain, or website for this article. A successful add is not proof that a network is honest. MetaMask does not offer technical support for every third-party chain that uses its wallet.
Sources
- MetaMask Support, How to add a custom network RPC: https://support.metamask.io/configure/networks/how-to-add-a-custom-network-rpc/
- MetaMask Support, Verifying custom network information: https://support.metamask.io/configure/networks/verifying-custom-network-information/
- MetaMask Support, User Guide: Custom networks and sidechains: https://support.metamask.io/more-web3/learn/user-guide-custom-networks-and-sidechains/
Disclosure: This article is informational coverage of MetaMask's help pages on custom networks and RPC endpoints. MetaMask does not verify custom networks. The featured image is a generated illustration, not a documentary photograph. This article is not financial, legal, or investment advice. AI-assisted research and writing. Cited sources, not AI alone, support the claims.