Chain ID in a crypto wallet: what it is and what it does
A chain ID is the number a wallet uses to identify an EVM network. The wallet signs it into a transaction so the signature fits only one chain.
Vahe HakobyanEditor-in-chief
Updated Oct 6, 20263 min readFact-checked
On this page
- Switching networks changes the active chain ID.
- Chain ID, name and RPC URL are separate settings.
- A chain ID is not your address or seed phrase.
You meet it in your wallet's network settings, beside the network name and the RPC address. Each network in your wallet's list has its own number.
How Do I Check My Wallet's Chain ID?
Open your wallet's settings and choose the network menu, where many wallets show each network's chain ID. Switching networks changes that ID.
What Happens With the Wrong Chain ID?
If the signed chain ID does not match the receiving network, that network rejects the transaction. A wallet set to another network sends a valid transaction there, so the funds land on that chain.
Chain ID vs Network Name and RPC
These settings sit together but do different jobs. The name is only a label your wallet shows you. The RPC URL is the address your wallet calls to reach a node, and the chain ID is a number the network itself sets. A token symbol names a token, not a chain.
How Does a Wallet Use the Chain ID?
On Ethereum-style networks, your wallet writes the chain ID into the transaction it signs. A node on another chain sees a number that does not match and rejects the signature. Chain IDs exist to stop a signed transaction from being replayed elsewhere.
Frequently asked questions
No. A network ID is an older identifier set separately, and it often matches the chain ID.
Not on its own. Your wallet asks you to approve a switch, and the ID changes only if you confirm.
No. Bitcoin has no EVM chain ID, and other networks use their own identifiers.
In the network's own documentation. Check a second source before you add one.
