Blockchain: Mining, Consensus & Chain Validation Simulator

Consensus mode

Mining difficulty 3 leading zeros

Chain length

–

Hash rate

–

Chain validity

–

How it works

Every block bundles a batch of transaction data together with the hash of the block before it, then runs the whole thing through a hash function. Because each block's hash depends on the previous block's hash, the blocks form a tamper-evident chain: editing any block changes its hash, which no longer matches what the next block recorded — breaking every link downstream.

H(i) = hash( data(i) + H(i-1) + nonce(i) )
Proof of Work:  search nonce until H(i) starts with D zeros
Proof of Stake: a validator is chosen by stake weight, no search needed

Mining difficulty — how many leading zero hex digits a Proof-of-Work hash must have; each extra digit multiplies the expected search space roughly ×16.
Consensus mode — Proof of Work grinds through nonces (slow, energy-heavy, very hard to rewrite); Proof of Stake instead picks a validator by stake and finalizes almost instantly.
Mine next block — appends a new block on top of the chain, animating the nonce search (PoW) or validator selection (PoS).
Tamper with a past block — edits an already-confirmed block's data and recomputes its hash live, showing every block after it turn invalid because their stored "previous hash" no longer matches.

This is the same mechanism that makes Bitcoin (PoW) and Ethereum (PoS since "the Merge") resistant to rewriting history: changing old data is detectable instantly because it breaks the hash chain, and reversing that would require redoing the consensus work or stake weight of every block since.

Confirmed block Mining / validating Invalid — hash mismatch Network node

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.