I have a smart contract with required message and pretend to use the required/validation message in front end.

require(bytes(hashAlreadyRegistered[hash]).length  == 0, "Hash already registered");

I'm trying to get the reason of revert using web3.eth.call.

By my understanding reading the doc if i pass the object generated by sendTransaction it will work. I think it is what i'm trying to do but didn't work so far.

My codes

sendTransaction method:

await canManipuleContract.methods.setDocumentHash('#_' + request.body.hash)
      from: fromAddress,
      gas: 400000,
      gasPrice: 21000000000
    .then(function(txRaw) {
      return response.json( txRaw.transactionHash );
    .catch(function(error) {
      console.log("Error: \n" + error);
      return response.json( 'error' )

web3.eth.call method:

function handleRevert( transactionObject ) {
    web3.eth.call( transactionObject, function( err, result ) {
      if ( ! err ) {
        console.log( 'result ' + result )
      console.log( 'err ' +  err)
      //return response.json( 'Error: Returned error: execution reverted' )

The return value of handleRevert is always err 0x. In geth console i clearly see the value err and errdata returning the correct messages.

If i pass the contract address instead transactionObject in web3.eth.call method it always return Error: Returned error: execution reverted, but never the required message it self.


Geth: 1.9.15-stable

web3.js: ^1.2.8

What am i missing here? Any others methods to get the message required of smart contract will help here.

4 Answers 4


Try this,

async function getRevertReason(txHash){

  const tx = await web3.eth.getTransaction(txHash)

  var result = await web3.eth.call(tx, tx.blockNumber)

  result = result.startsWith('0x') ? result : `0x${result}`

  if (result && result.substr(138)) {

    const reason = web3.utils.toAscii(result.substr(138))
    console.log('Revert reason:', reason)
    return reason

  } else {

    console.log('Cannot get reason - No return value')


  • 1
    Oh yes, it works. But i'm not been able to get the txHash of the var error of catch block to pass into getRevertReason function. With e.g. console.log( "Error: \n" + errorTransaction ) it prints the entire object of reverted transaction. If i for example console.log( "Error: \n" + errorTransaction.transactionHash ) or any other property it throws undefined. any tip here? Jun 27, 2020 at 1:19
  • 1
    i already tried to transform the object error to json and then parse or split it, but didn't sucessed. Jun 27, 2020 at 1:27
  • 1
    also tried to change the send method to use callback but error callback always return null instead the reverted transaction. Jun 27, 2020 at 1:56
  • 1
    remove await or write code inside try, catch block Jun 29, 2020 at 9:33

Web3 supports revert strings now: https://web3js.readthedocs.io/en/v1.2.8/web3-eth.html#handlerevert.

You can activate it easily by setting web3.eth.handleRevert = true. Now when you use call or send functions, precisely one of the following:

  • web3.eth.call()
  • web3.eth.sendTransaction()
  • contract.methods.myMethod(…).send(…)
  • contract.methods.myMethod(…).call(…)

you will see a new message like

Error: Your request got reverted with the following reason string: This is the revert reason!
  • didn't work. I put web3.eth.handleRevert = true after beside the provider. e.g. const canManipuleContract = createContract(contractAddress), web3.eth.handleRevert = true; Jun 27, 2020 at 1:22
  • @RAFAELDASILVA It seems there is a Web3 bug for geth 1.9.5. It's already fixed: github.com/ethereum/web3.js/pull/3571 but you'll have to wait for the next Web3 version to be released. Jun 27, 2020 at 3:21
  • this unfortunately doesn't work. "invalid arrayify value'"
    – noooooooob
    Feb 22, 2021 at 6:05

There is a handleRevert property in web3 itself. For me, it only works when I set web3.handleRevert = true instead of the documented option, web3.eth.handleRevert = true. The error message comes back in the reason attribute of the Error object that is thrown by the send() call of a smart contract method.


Follow this. Basically different RPC's will have different error response data. So you'll have to check the response and then simply use parseError on contract's interface.


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