I know this question has been asked many times before. I've read loads of answers, but nothing seems to work for me. I first tried to verify the source code of a much larger, more complex contract, but it didn't work, so I wrote a very simple tiny contract in Solidity:

pragma solidity ^0.4.17;

contract SimpleTest
    string public blablabla;
    function SimpleTest() public
        blablabla = "Hello world!";

As you can see, I'm not using any constructor arguments, import statements or libraries. I compiled and deployed it using Solidity 0.4.17 from inside Parity. Optimization was enabled. I did not use one of the nightly builds.

Contract creation transaction:


The contract in question:


Link to the verification page:


The error message I get from etherscan.io is:

Sorry! The Compiled Contract ByteCode for 'SimpleTest' does NOT match the Contract Creation Code for [0x5a8b57a6cf17a196e000eca4481257d5d3025636]

Contract name(s) found: 'SimpleTest'

Unable to Verify Contract at this point time.

I've analyzed the bytecodes a little bit, and I found that:

  • The input data of the contract creation transaction is exactly equal to the bytecode I got from Parity.

  • The bytecode that the etherscan.io verifier produces is similar to the bytecode from Parity, and thus also similar to the input data of the contract creation transaction.

  • The bytecode on the contract page on etherscan.io is much shorter than the other bytecodes.

  • All the bytecodes contain 2 large strings of 00 bytes, except the bytecode on the etherscan.io contract page, it only contains 1 large string of 00 bytes.

I really have no idea what's going on here. Can anyone help?


1 Answer 1


I was able to verify my contract with optimization turned on, when compiling from remix:


For some reason, it produces a different bytecode from Parity, even if you select the same compiler version and the same optimization setting.


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