How do I convert the result returned from a JSON-RPC eth_call from my geth client?

This is the call: curl -X POST --data '{"jsonrpc":"2.0","method":"eth_call","params":[{"to":"0x86312d97c0dd3fd9202fdbdec434f36ee1b30720", "data":"0x18160ddd"}, "latest"],"id":1}'

This is the return: {"jsonrpc":"2.0","id":1,"result":"0x00000000000000000000000000000000000000000000000000000000000f4240"}

How to convert: 0x00000000000000000000000000000000000000000000000000000000000f4240 back to human readable characters?

  • use toasci funtion Jul 14, 2017 at 13:53
  • I've tried web3.toAscii("0x00000000000000000000000000000000000000000000000000000000000f4240") and this is what I get: "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x0fB@"
    – Jupiter
    Jul 14, 2017 at 13:56
  • 1
    it depends on the return of your function toasci will work only if it return a string Jul 14, 2017 at 13:57
  • Yes! that is the answer. Trivial actually.
    – Jupiter
    Jul 14, 2017 at 14:00

1 Answer 1


Its Hex encoded string you can convert it in to Decimal.

For web3: web3.toDecimal('0x00000000000000000000000000000000000000000000000000000000000f4240')

For javascript: parseInt('0x00000000000000000000000000000000000000000000000000000000000f4240', 16);

For PHP: hexdec('0x00000000000000000000000000000000000000000000000000000000000f4240');

// result: 1000000

For other programming languages you can search for hextodecimal function for that particular programming language.

  • Sometimes one needs to use bignumber.js - I've received the following result 2e+21 which wouldn't work with the functions above, would only work with BigNumber(2e+21).toString(10)
    – Asaf
    Apr 19, 2018 at 12:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.