What is Validator?
A validator is a node operator on a proof-of-stake blockchain that stakes the network's native token to propose and attest to new blocks in exchange for staking rewards.
What is a Validator?
In a proof-of-stake blockchain, a validator is the equivalent of a miner in Bitcoin. Instead of solving hash puzzles, validators lock up capital ("stake") as a security deposit and take turns proposing blocks. Their job is to confirm that transactions are valid, keep the network honest, and finalize the chain's history.
What Validators Actually Do
- Block proposal: When selected, a validator builds and broadcasts the next block.
- Attestation: Other validators vote on whether the proposed block is valid.
- Finality: Once a supermajority attests, the block becomes irreversible.
- Monitoring: Validators run nodes 24/7 and must respond quickly to avoid downtime penalties.
Staking Requirements
Requirements vary by network. Ethereum requires 32 ETH per validator. Cosmos and Polkadot have lower minimums but competitive slot limits. Delegators can contribute without running a node by assigning stake to a professional validator, splitting the rewards.
How Validators Earn
Rewards come from two sources: newly minted tokens and transaction priority fees. Validators keep a commission (typically 5–10%) from delegators before distributing the rest. On Ethereum, MEV (maximum extractable value) also contributes meaningfully to validator revenue.
Risks: Slashing and Downtime
Validators who go offline lose minor rewards. Those who sign conflicting blocks or equivocate can be slashed — losing a significant portion of their stake. Reliable infrastructure, redundant setups, and careful key management are essential for anyone running a validator.