Skip to main content
Returns the ETH balance of an address at a given block.
Flashblocks: Query https://mainnet-preconf.base.org with "pending" to read balances updated every ~200ms — before the block seals.

​
Parameters

​
address
string
required
The 20-byte address to query.
​
block
string
required
Block number in hex, or "latest", "pending", "safe", "finalized", "earliest". Use "pending" on a Flashblocks endpoint for pre-confirmed balance.

​
Returns

​
result
string
The balance in wei as a hexadecimal string.

​
Example

curl https://mainnet.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": ["0x742d35Cc6634C0532925a3b8D4C9dD0b4f3BaEa", "latest"],
    "id": 1
  }'