By default there are 24 confirmations but I am running a testnet with just 3 miners and I would like to change this number bucause it makes not sense to have 24. I have been checking transactionConfirmationBlocks on the following way:

const options = {
   transactionConfirmationBlocks: 3

var web3 = new Web3(new Web3.providers.WebsocketProvider(provider_string, options));

I am not getting errors, but when I make a transaction it is still making 24 confirmations. if I check the number of confirmations (web3.eth.transactionConfirmationBlocks) is still 24. What is the right way to set the number of confirmations?

  • I think the options have to be passed as a second argument to new Web3(..) rather than ...WebSocketProvider(..). Feb 15, 2019 at 18:19
  • I did it and it has the same behaviour Feb 15, 2019 at 18:27

2 Answers 2


You need to pass the options parameter to Web3, not to WebsocketProvider, like this:

const options = {
   transactionConfirmationBlocks: 3

const web3 = new Web3(
  new Web3.providers.WebsocketProvider(provider_string),

According to the docs it can also be set like this:


You tryed this?

const Web3 = require('web3')

const options = {
    transactionConfirmationBlocks: 24,

const web3 = new Web3('http://localhost:8545', null, options);

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