Handy Geth Commands See balance of (all) account(s) > for (var i=0; i<web3.eth.accounts.length; i++) { console.log(web3.eth.accounts[i]+" has "+web3.eth.getBalance(web3.eth.accounts[i])); } Fix "ReferenceError: 'accounts' is not defined". > web3.eth.defaultAccount = web3.eth.accounts[0] Fix "Error: authentication needed: password or unlock" > personal.unlockAccount(web3.eth.defaultAccount, 'password')