Mining controls
Edit the example header and transaction data. The Merkle root is illustrative; the simulator adds the chain’s previous-hash link automatically.
Each new block includes the previous block's hash. Higher difficulty can take a long time; try the quick demo first.
Live mining
Click “Start mining” to search for a valid hash.
Elapsed0 s
Hashes / second0
Expected wait…
Block mined successfully!
Nonce
Resulting hash
Expected wait is not a countdown. Each hash is a new independent attempt, so the remaining expected wait does not decrease as attempts fail.
Live performance
Compare the last five runs with different thread counts. The chart shows measured hashes per second, not simulated speed. Device load and browser scheduling affect results.
Start mining to see your first performance curve.
| Run | Threads | Zeros | Average H/s | Peak H/s | Elapsed | Result |
|---|
Blockchain tampering lab
Create demo blocks or mine your own, then edit an earlier block. Its hash changes, breaking the next block's stored link. Repairing re-mines the affected blocks in order.
Demo blocks use 2 leading zeros for quick experiments. This local chain has no network consensus; real Bitcoin also requires competing with the network's accumulated work.
Miner race
Probability simulationSet three miners' relative hash power and run 30 rounds. A miner with twice the power has twice the chance per round, but can still lose.
This is a mathematical model, not a hardware benchmark. Each miner gets an independent random waiting time; the first wins. Bars show observed win shares, not progress toward finding a hash. Small samples can differ from expected probabilities.