Blockchain nodes: full, pruned, light and archive
The computers that actually enforce the rules, and why running one matters more than mining.
A node is a computer running a blockchain's software. Full nodes download and check every block against the rules themselves; pruned nodes do the same but delete old blocks afterward; archive nodes keep every historical state; light nodes download only block headers and rely on full nodes for the rest. Miners and validators produce blocks, but it's the nodes that decide whether to accept them.
The four kinds of node
- Full node. Downloads every block from the beginning and checks every signature, every spend and every rule. It trusts nobody. On Bitcoin this is Bitcoin Core (or another implementation) with default settings; on Ethereum it's an execution client plus a consensus client.
- Pruned node. A full node that deletes old block data once it's been checked, keeping only what it needs to verify new blocks. Bitcoin Core can prune down to 550 MiB of blocks. It's just as secure for checking new payments, but it can't serve old blocks to others.
- Archive node. Keeps everything, including every past state. On Ethereum, a normal full node keeps only recent state (roughly the last 128 blocks), while an archive node can answer "what was this balance at block 5 million?" It needs terabytes of storage, and it's mostly run by block explorers, analytics firms and data providers.
- Light node (light client). Downloads only block headers and asks full nodes for specific data, checking it against those headers with Merkle proofs. The Bitcoin white paper calls this "simplified payment verification" (SPV). Ethereum light clients follow a rotating "sync committee" of 512 validators.
Nodes, miners and validators: who does what
| Role | What it does | Needs |
|---|---|---|
| Full node | Checks and relays blocks and transactions; rejects anything invalid | A normal computer, a large SSD, a steady internet connection |
| Miner (proof of work) | Competes to produce the next block | Specialized ASIC machines and cheap electricity; most join pools |
| Validator (proof of stake) | Proposes blocks and votes on them | A full node plus validator software and staked coins (on Ethereum, at least 32 ETH per validator) |
The key point: block producers propose, nodes dispose. If miners or validators produce a block that breaks the rules, for example by creating extra coins, full nodes simply ignore it. That's why Bitcoin users talk about running a node as the way to "vote" on the rules (see forks).
How many nodes are there?
Nobody knows exactly, because nodes don't register and many don't accept incoming connections. Treat every count as a rough estimate:
- Bitcoin: the long-running Bitnodes crawler's estimate was in the 20,000s in April 2026, before its domain expired in May 2026; other trackers gave figures from about 14,000 to over 90,000 depending on what they count (Protos, May 20, 2026). Counts that include nodes behind home routers are much higher than "reachable" counts.
- Ethereum: Etherscan's node tracker showed 11,749 execution-layer nodes when we checked on November 4, 2026.
- Ethereum validators are not nodes. There were about 863,000 active validators in early October 2026, down from about 975,000 at the start of the year as large stakers merged validators after the 2025 Pectra upgrade let one validator hold up to 2,048 ETH. A single node can run thousands of validators, so the validator count says little about how many independent machines exist.
Should you run one?
You don't need a node to use crypto; your wallet connects to someone else's. Running your own gives you three things: you verify your own payments instead of trusting a company's server, your wallet stops telling that server which addresses are yours, and you add one more independent copy of the rules. A Bitcoin full node needs several hundred gigabytes of storage (or far less if pruned) and runs on a modest computer. An Ethereum full node needs a fast SSD of a couple of terabytes.
Limitations
- Light clients trust a little. They assume the chain their peers show them follows the rules. They can't detect an invalid block on their own the way a full node can.
- Node counts don't equal decentralization. Many nodes run in a few cloud providers, and most Ethereum nodes run one of a handful of client programs. A serious bug in a dominant client is a bigger risk than a low node count.
- Hosting a node doesn't make you money. Plain nodes earn nothing; be wary of "node" investment schemes promising returns, a common scam pitch.
Frequently asked questions
Do I earn crypto by running a node?
No. A plain full node earns nothing. Rewards go to miners and validators. Offers to "invest in a node" for a fixed return are a common scam.
Is a pruned node a full node?
Yes, in the sense that matters: it downloaded and checked every block itself. It just deleted old block data afterward.
What is an SPV wallet?
A light wallet that uses "simplified payment verification" from the Bitcoin white paper: it downloads block headers and checks Merkle proofs that its transactions are included, without checking every rule.
Why do Ethereum nodes need two programs?
Since the Merge in 2022, Ethereum splits the work: an execution client runs transactions and smart contracts, and a consensus client follows proof of stake. A full node runs both.
How many validators does Ethereum have?
About 863,000 active validators in early October 2026. That number has been falling since Pectra let one validator hold up to 2,048 ETH, even as the total ETH staked rose.
Where to next
Sources
- Bitcoin white paper, section 8 (simplified payment verification)
- Running a full node (bitcoin.org)
- Nodes and clients (ethereum.org)
- Light clients (ethereum.org)
- Bitcoin node counters go dark following Bitnodes expiry (Protos, May 2026)
- Ethereum node tracker (Etherscan)
- Ethereum active validators fall to about 863,000 (PrimeXBT, October 2026, citing Crypto Briefing)
- Pectra upgrade (ethereum.org)
Written for beginners and checked against the sources listed. Last reviewed November 4, 2026. This page is educational and is not financial, tax or legal advice. How we write and check pages.