Topic · How blockchains work
What is a validator in crypto?
- Quick fact 1
On Ethereum, a validator deposits 32 ETH to activate and take part in consensus.
- Quick fact 2
Validators earn rewards and can be penalized or slashed for misbehavior.
- Quick fact 3
Ethereum switched from proof of work to proof of stake in The Merge in September 2022.
Source: ethereum.org: The Merge
The short lesson
On a proof-of-stake blockchain, validators do the job miners do in proof of work: they add and check blocks.
Instead of burning electricity, a validator locks up coins as a stake. On Ethereum, that is 32 ETH per validator. The network picks validators to propose new blocks and asks others to vote (attest) that the blocks are valid.
Carrots and sticks
- Rewards for doing the job well and on time.
- Penalties for being offline.
- Slashing for provable cheating, such as signing two conflicting blocks. Part of the stake is destroyed and the validator is removed.
How this connects to “staking” products
Many people never run a validator. They use a staking service or pool. That adds company risk: who holds the keys, what are the fees, and can you withdraw? Read what is staking and are staking rewards taxable.
Lesson game · earn XP
Check yourself: 3 quick questions
Perfect score = combo bonus. Each question returns in your spaced-repetition review.
Memory · spaced repetition
Flashcards: lock it in
Flip each card, then say if you knew it. Missed cards come back sooner.
Related terms
Go deeper in Lesson 4: The shared list everyone can check
More in How blockchains work
Common questions
Do I need 32 ETH to stake?
To run your own Ethereum validator, yes. Pools and services accept less, with extra risks.
What is slashing?
A penalty that destroys part of a validator’s stake for provable rule-breaking.
Is a validator the same as a node?
A validator runs on a node, but many nodes do not validate.
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Reviewed and sources
Written and reviewed by Joshua Baskin, founder. Last reviewed . How we check facts · Report an error
Education only. Not investment, tax or legal advice. We do not pick coins.