Glossary

Validator

Plain-language definition Crypto glossary

Key takeaways

A validator is a participant in a proof-of-stake blockchain responsible for checking transactions and helping add new blocks, making them the proof-of-stake equivalent of miners.
To become a validator, a participant stakes a required amount of the network's coin as collateral, and the protocol selects validators to propose and attest to blocks, rewarding honest work with newly issued coins and fees.
Misbehaviour such as confirming invalid blocks can be punished by "slashing," and the number and spread of validators is a key measure of how decentralized and secure a network is.

Definition

A validator is a participant in a proof-of-stake blockchain responsible for checking transactions and helping add new blocks. Validators are the proof-of-stake equivalent of miners.

How it works

To become a validator, a participant locks up — stakes — a required amount of the network’s coin as collateral. The protocol then selects validators to propose and attest to new blocks, rewarding honest work with newly issued coins and fees. Misbehaviour, such as trying to confirm invalid blocks, can be punished by “slashing,” which destroys part of their stake.

Why it matters

Validators secure proof-of-stake networks using economic incentives rather than the energy-intensive computation of mining. The number and spread of validators is a key measure of how decentralized and secure such a network is.

Example

Someone who stakes the required amount and runs validator software helps secure the network and earns staking rewards.

FAQ

Frequently asked questions

How are validators different from miners?

Validators secure proof-of-stake networks using staked collateral and economic incentives, whereas miners secure proof-of-work networks through energy-intensive computation. Validators are essentially the proof-of-stake equivalent of miners, achieving the same goal of confirming transactions without the heavy energy cost.

What happens if a validator misbehaves?

If a validator tries to confirm invalid blocks or otherwise breaks the rules, it can be punished by slashing, which destroys part of its staked collateral. This penalty aligns validators' incentives with honest behaviour.

Why does the number of validators matter?

The number and spread of validators is a key measure of how decentralized and secure a proof-of-stake network is. A larger, more distributed set of validators makes the network harder to attack or control.