Several block explorers are reporting that the nonce value in many block headers is 0. For example, blockcypher,

Why does this happen?

Where can I get the actual block headers?

1 Answer 1


This appears to be a bug in their software (i.e. it occurs for no reason other than it's a mistake) so you should report this to Blockcypher.

  • Contacted Blockcypher but the same block works fine for them at blockcypher.com/dev/bitcoin/#blockchain "bits": 419486617, "nonce": 1225187768, but what is modified now is hash (abbreviated) "hash": "0000000000000000189bba3564a63772107b567...", Should I contact Fed Governor Powell under Federal Reserve Bitcoin Strategy and report the case if no remedy by Blockcypher?
    – darius
    Commented Dec 29, 2017 at 5:19
  • What are you talking about? Regardless, there is no reason for them to show this other than a bug in their software. Whether they fix it or not is completely up to them. In the meantime, if you need the data that they are incorrectly showing, you should use some other API.
    – Ava Chow
    Commented Dec 29, 2017 at 5:31
  • Trust in Bitcoin is based on reliability of Bitcoin data like blocks, block header and more. If we let such sensitive data to be manually modified and manipulated by third parties, trust in Bitcoin may one day get lost, hurting FED and economy the most. If you advise me to hide such foul play from FED I have no experience to make such decision on my own. Do you know any other API for historic block header data download ?
    – darius
    Commented Dec 29, 2017 at 5:45
  • Trust in Bitcoin has very little to do with the third party data providers. They are not official in any way nor are they supposed to be an authoritative source of data. The data retrieved from them can be validated yourself. If the third party is not trusted, then run a full node yourself and get the data. Full nodes don't use these third parties; they download the blocks directly from other peers and validate them. Furthermore, there are several API providers such as Blocktrail, blockchain.info, chain.so, etc.
    – Ava Chow
    Commented Dec 29, 2017 at 5:50
  • blocktrail.com/api/docs is another Bitcoin service removing "nonce" from hashed blocks: vide example . Description to the left is full. What is returned via API as block example is nonce removed block data.Nonce following difficulty is missing.
    – darius
    Commented Dec 29, 2017 at 6:16

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