What is a validator?
A validator is a participant in a proof-of-stake blockchain that checks transactions and takes part in adding new blocks. The idea comes from Proof of Stake (PoS), where the right to take part in consensus depends on how much of the network's token is locked up, not on computing power.
In practice, a validator is a Node that runs the network's software and holds a signing key. Some tokens are attached to that key as collateral. If the validator follows the rules, it earns rewards. If it breaks them, part of the collateral can be destroyed.
You may also see the misspelling "validater", or the phrase "block producer". Both usually point to the same idea, although "block producer" has a slightly narrower meaning on some networks. It is explained further down this page.
The word "validator" is also used in ordinary software, for example form validators and email validators. This page covers only the blockchain meaning.
What validators do
Details differ between networks. The steps below use Ethereum as the main example, because its documentation is public and widely read.
Verify transactions
Validators check that each transaction follows the protocol rules. For example, the sender must have enough balance and a valid signature. Invalid transactions are rejected and do not enter a block.
Propose and attest to blocks
On Ethereum, time is split into 12-second slots, and one validator is pseudo-randomly chosen as the block proposer for each slot. A randomly chosen committee of other validators then votes, called attesting, on whether the proposed block is valid. Slots are grouped into an Epoch of 32 slots, and every active validator attests once per epoch.
Reach consensus
Consensus means that independent validators agree on one version of the ledger. On Ethereum, a checkpoint block becomes final once validators holding at least two thirds of the total staked ETH have voted for it. Undoing a finalized block would cost an attacker at least one third of all staked ETH.
A validator does three jobs: it checks transactions, it proposes or votes on blocks, and it helps the network agree on one history. Its collateral gives it a financial reason to do those jobs honestly.
Validator vs miner vs node
These three words overlap, and people often mix them up. A Miner (Crypto Miner) works on proof-of-work chains such as Bitcoin, where the right to add a block is won by spending computing power and electricity. A validator works on proof-of-stake chains, where the right is linked to staked tokens.
A node is the broadest term. Any computer that keeps a copy of the blockchain and relays data is a node. A validator is a node that has taken on extra duties and put collateral at risk.
| Term | Role | What is at risk |
|---|---|---|
| Validator | Verifies and votes on blocks on proof-of-stake chains | Staked tokens, through slashing |
| Miner | Competes to solve puzzles on proof-of-work chains | Hardware and electricity costs |
| Node | Keeps a copy of the chain and relays data | Usually no stake; running costs only |
Many people can run a regular node without earning anything. Not every validator needs to be run by the token holder either, as the section on delegation explains.
How to become a validator
Requirements vary a lot by network and change over time, so always check the official documentation before acting. The figures below were checked against official documentation in 2026.
- Ethereum: A validator needs at least 32 ETH to activate. Since the Pectra upgrade on 7 May 2025, a validator with compounding withdrawal credentials can hold up to 2,048 ETH.
- Ethereum hardware: ethereum.org gives a rough guide of a 4 TB NVMe SSD, 64 GB of RAM, a modern multi-core CPU and about 50 Mbps download and 25 Mbps upload.
- Solana: The Agave documentation says there is no strict minimum SOL, but a vote account needs a small rent-exempt reserve. Voting can cost up to about 1.1 SOL per day in transaction fees.
- Solana hardware: the documentation lists 12 cores or more, 256 GB of RAM or more, several fast NVMe disks and a network connection of at least 2 Gbit/s for a staked node.
- Cosmos Hub: There is no fixed minimum stake, but only the 180 validators with the most delegated ATOM are in the active set, so in practice the barrier is attracting delegations.
Uptime also matters. A validator that is offline misses duties, and on some networks long downtime leads to penalties. Serious operators use monitoring, backups and stable connections.
- Choose a network and read its official validator documentation.
- Prepare hardware or a cloud server that meets the stated requirements.
- Generate and safely store the validator keys and any withdrawal keys.
- Install and sync the required software, then make the deposit or register the validator.
- Monitor the validator continuously and keep the software updated.
Running the same validator keys on two machines at once can cause a slashable double vote. Mistakes in key handling or setup can cost real money. This page is general education, not technical or financial advice.
Delegation and staking pools: earning without running a node
Most holders do not run their own validator. Instead they hand their tokens to someone who does. The usual routes are delegation, pooled staking and Staking through a service.
On networks such as Cosmos Hub, token holders delegate to a validator. The validator's voting power equals the total amount delegated to it, and the delegator shares in the rewards, minus the validator's commission. Chains built around this model are often described as Delegated Proof of Stake (DPoS) or as using delegated staking.
Pools combine many small deposits so that a person with less than the minimum can take part. Some pools give the user a receipt token that can be traded or used elsewhere. That design is called Liquid Staking.
Delegating does not remove risk. On Cosmos Hub, slashing can apply to delegated tokens as well as the validator's own. Pools and liquid staking add smart contract, custody and platform risks. Terms differ by provider, so read them closely.
Validator rewards and commission
Validators earn Staking Rewards from the protocol. Depending on the network, these come from newly issued tokens, transaction fees, or both. On Ethereum, rewards depend on how long the validator is online and how well it attests, and late attestations earn less.
A solo Ethereum staker keeps the protocol rewards, according to ethereum.org, but pays all running costs. Solana validators also pay vote transaction costs, as noted above.
When a validator serves delegators, it usually sets a commission, which is a percentage of the delegators' rewards that the validator keeps. A lower commission is not automatically better. Reliability, security practices and the validator's track record matter too.
- Rewards are variable, not fixed. They change with network activity, total amount staked and the validator's own performance.
- Quoted yields are snapshots and can fall as more tokens are staked.
- The token's market price can fall by more than any reward earned.
- Tax treatment of rewards depends on where you live. Ask a qualified local adviser or check your tax authority's guidance.
Slashing, downtime and other risks
Slashing
Slashing is a penalty in which part of a validator's stake is destroyed. On Ethereum, validators can be slashed for proposing more than one block in the same slot, or for sending contradictory attestations. A slashed validator is forced out of the network over several weeks.
The size of the penalty depends on how many other validators are slashed around the same time. According to ethereum.org, it can be under 0.1% of stake for an isolated case, and up to 100% in a mass slashing event. On Cosmos Hub, validators that double sign, or stay offline for an extended period, can be slashed, and this includes delegated tokens.
Downtime
On Ethereum, being offline is not slashing. The validator loses a little reward through inactivity penalties, and it can recover by coming back online. If more than a third of validators go offline and the chain stops finalizing, an inactivity leak gradually drains the offline validators' balances.
Other risks
- Software bugs: a flaw in a widely used client can cause many validators to fail or be penalized at once.
- Key theft or loss: whoever controls the keys may control the stake or the validator.
- Lock-up: tokens may be locked, or exit may take time because of queues or unbonding periods.
- Counterparty risk: pools, exchanges and liquid staking providers can fail or be hacked.
- Price risk: the staked token can lose value regardless of rewards.
Staking can lead to partial or total loss of the staked amount. Nothing about validator rewards is guaranteed. Only stake what you can afford to lock up and possibly lose.
Validator selection and decentralization
Networks choose validators in different ways. On Ethereum, a proposer is picked pseudo-randomly for each slot, and every active validator takes part in voting. On Cosmos Hub, the top 180 validators by delegated stake form the active set. EOS uses a smaller set of elected block producers.
Decentralization depends on how widely stake is spread. If a few validators, pools or custodians control a large share, the network relies on a small number of parties. In many proof-of-stake designs, a group holding more than one third of the stake could stall finality, so concentration is a real security question.
Concentration can build up even when the network has many validators. Delegators tend to choose well-known names, and one staking provider can run thousands of validators. Spreading stake across several independent operators is one way the community tries to keep the network healthy.
Because the numbers change often, check a current, neutral network explorer or dashboard instead of relying on a fixed figure.
Validator examples by network
The table below is a snapshot based on official documentation checked in 2026. Networks change their rules, so confirm current details before relying on them.
| Network | Who validates | Notable detail |
|---|---|---|
| Ethereum | Validators with staked ETH | 32 ETH to activate; up to 2,048 since Pectra (May 2025) |
| Solana | Validators with a vote account | No strict minimum SOL; voting costs up to 1.1 SOL a day |
| Cosmos Hub | Top 180 validators by delegated ATOM | Delegators share rewards and slashing risk |
| EOS | 21 active block producers | Elected by token holder votes |
The term "block producer" is used mainly on delegated chains such as EOS, where a small elected group produces and signs blocks. On proof-of-stake chains like Ethereum, the same job is usually called a block proposer, and the broader word "validator" covers both proposing and voting. The networks above are neutral examples, not recommendations or a complete list.
Frequently asked questions
What is a validator in crypto?
A validator is a participant in a proof-of-stake blockchain that checks transactions, proposes or votes on new blocks and helps the network agree on one ledger. Validators lock up tokens as collateral and earn rewards for honest work. If they break the rules or stay offline too long, part of their stake can be slashed.
What is the difference between a validator and a miner?
A miner secures a proof-of-work chain by spending computing power and electricity to compete for the right to add a block. A validator secures a proof-of-stake chain by locking up tokens as collateral and following the protocol. Miners risk wasted hardware and energy costs, while validators risk losing staked tokens through slashing.
How do validators get paid?
Validators are paid by the protocol, usually in the network's native token, from newly issued tokens, transaction fees or both. Rewards depend on uptime and correct behavior. Delegated validators typically keep a commission from delegators' rewards. Amounts are variable and not guaranteed, and the token's price can change, so rewards can be lost in value.
What is slashing?
Slashing is a penalty that destroys part of a validator's stake when it breaks serious protocol rules, such as signing two conflicting blocks or votes. The validator is usually removed from the active set. Delegated tokens can also be affected on some networks. Simple downtime is often penalized less harshly than slashing, depending on the network.
How much do you need to become a validator?
It depends on the network. Ethereum needs at least 32 ETH to activate a validator, and up to 2,048 ETH can be held in one since the Pectra upgrade in May 2025. Solana has no strict minimum SOL but has high hardware and running costs. On Cosmos Hub, you need enough delegated stake to rank in the top 180. Check official documentation first.
What does 'block producer' mean?
A block producer is a participant that creates and signs new blocks. The term is common on delegated proof-of-stake networks such as EOS, where token holders vote for a small set of producers, 21 by default. On other chains the same role is called a block proposer, and the wider term validator also covers the voting side.
Related terms
- Proof of Stake (PoS)
- Staking
- Node
- Miner (Crypto Miner)
- Delegated Proof of Stake (DPoS)
- Epoch
- Staking Rewards
- Liquid Staking
Sources
- Solo staking ethereum.org
- Proof-of-stake (PoS) ethereum.org
- The Pectra upgrade ethereum.org
- Agave Validator Requirements Anza
- Cosmos Hub validators overview Cosmos documentation
- Consensus protocol EOS Network Foundation docs
This glossary entry is for general information and education only. It is not investment, tax or legal advice. Crypto assets are high-risk; check official sources before you act.