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What is a validator?
A validator is a participant in a proof-of-stake network that has locked up coins and runs software to check blocks, vote on them and sometimes propose new ones. On Ethereum, activating a validator takes a deposit of 32 ETH.
What it means for you
A validator that goes offline loses small amounts of its stake, and one that breaks the rules, such as proposing two blocks for one slot, can be slashed by up to its whole deposit. If someone else runs a validator for you, their mistakes cost your ETH.
How it works
An Ethereum validator is a 32 ETH deposit in the deposit contract plus three programs: an execution client, a consensus client and a validator client. In each 12-second slot one validator is picked at random to propose a block, and committees of others vote on it; missing these duties forfeits rewards. If the chain fails to finalize for more than four epochs, an inactivity leak gradually drains the stake of validators not voting with the majority. Proposing two blocks in one slot or signing contradictory votes is slashed: an immediate penalty, a later correlation penalty that grows when many are slashed together, and forced exit after about 36 days.
Sources: ethereum.org: Proof-of-stake, ethereum.org: Staking · checked 4 October 2026
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