Computers that check the rules instead of trusting someone else’s copy.
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If everyone in a game can check the score themselves, a referee cannot quietly award a million extra points.
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Receive, check and share across independent nodesStep 1 / 4
A node receives a proposed transaction or block-related message. Receipt is not the same as accepting its claims.
A node receives a proposed transaction or block-related message. Receipt is not the same as accepting its claims.The node checks the relevant authorization and protocol rules. Popularity does not make an invalid state transition valid.Valid candidate data can propagate to peers. Connections and timing differ, so there is no perfect simultaneous worldwide view.Peers validate under the same protocol rules. This illustration is about verification and propagation, not a complete proof-of-stake consensus algorithm.
Animated local teaching model. No wallet, RPC or live blockchain data. Some labels and hashes are abbreviated for readability.
What a node does
A node runs Ethereum client software. It receives blocks, checks transactions and maintains information about the chain. Running your own node lets you verify answers instead of fully trusting a hosted service. Different node types retain different amounts of historical data.
Execution and consensus
An Ethereum node normally uses an execution client and a consensus client. The execution side checks transactions and the EVM. The consensus side follows proof of stake and the choice of chain. A validator also needs validator software and the appropriate stake.
Reading is different from writing
A wallet can ask a node for a balance or simulate a call through JSON-RPC. This does not itself make a new onchain transaction. Writing persistent changes requires a transaction that the network accepts. A hosted RPC can have limits or costs even when a read does not consume onchain gas.
Why this site works offline
Our tools calculate from the inputs in your browser. They do not query balances, resolve ENS names or broadcast transactions. That makes experiments repeatable without API keys. A valid result in a local decoder describes those bytes, not the current state of a real contract.
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Must a node also be a validator?
A node can independently verify Ethereum without proposing or attesting to blocks as a validator.