Merkle Tree Calculator
Compute the Merkle root and tree of a list of leaves — SHA-256 or Bitcoin double SHA-256, in your browser.
🔒 100% in your browser — nothing is uploaded
How it works
Enter one leaf per line to build a Merkle tree and get its root. Each leaf is hashed, then hashes are paired and re-hashed level by level (duplicating the last node on odd levels) up to a single root. Choose plain SHA-256 or Bitcoin-style double SHA-256. It runs entirely in your browser.
Frequently asked questions
What is a Merkle tree?
A tree of hashes where each parent is the hash of its two children. One small root hash commits to a whole set of data, so any change to any leaf changes the root.
Why does Bitcoin use Merkle trees?
Each block summarises all its transactions in one Merkle root, letting lightweight clients verify that a transaction is included without downloading the whole block. Bitcoin uses double SHA-256.
What happens with an odd number of leaves?
The last node is duplicated and paired with itself, the same rule Bitcoin uses, so every level can be paired.