eth_blockNumber | Optimism

Optimism API method that returns the latest block number of the blockchain. A block number is a hexadecimal number representing the block's position in the blockchain. For example, the block number 0x69B5B means that the block is block 432987 in the blockchain.


Get you own node endpoint today

Start for free and get your app to production levels immediately. No credit card required.

You can sign up with your GitHub, X, Google, or Microsoft account.


  • none


  • result — the integer value of the node's latest block number is synced to, encoded as hexadecimal. The block number is used to identify the block's position in the blockchain and is updated every time a new block is added to the chain.

Use case

A possible use case for the eth_blockNumber method in Optimism is for applications that need to be aware of the current block number—some applications may need to be mindful of the current block number to function correctly. For example, a DApp may use the current block number to determine the expiration date of a time-limited offer.

Try the eth_blockNumber RPC method yourself

Click Try It! to start a request and see the response here!