Bitcoin Block Header Builder

Explore and reconstruct valid Bitcoin block headers. Input block data or load from the blockchain to simulate SHA-256 hashing and test valid combinations.

Enter a block number to retrieve and analyze its header details.

What is a Bitcoin Block Header?

The block header is a 80-byte section at the beginning of each block in the Bitcoin blockchain. It contains crucial metadata that identifies the block and links it to the chain, including:

  • Version: Indicates the block's version.
  • Previous Block Hash: Links to the preceding block, forming the blockchain.
  • Merkle Root: A hash representing all transactions included in the block.
  • Timestamp: The time when the block was created.
  • Bits: A compact representation of the target difficulty.
  • Nonce: A number used by miners during the proof-of-work process.

These components work together to ensure the integrity and security of the blockchain. Mining involves adjusting the nonce to find a block header hash that meets the required difficulty, thereby proving the computational work done.