Nodes and clients
Last edit: , Invalid DateTime
Ethereum is a distributed network of computers (known as nodes) running software that can verify blocks and transaction data. The software application, known as a client, must be run on your computer to turn it into an Ethereum node.
Note: it is not possible to run an execution client on its own anymore. After The Merge, both execution and consensus clients must be run together in order for a user to gain access to the Ethereum network.
You should understand the concept of a peer-to-peer network and the basics of the EVM before diving deeper and running your own instance of an Ethereum client. Take a look at our introduction to Ethereum.
If you're new to the topic of nodes, we recommend first checking out our user-friendly introduction on running an Ethereum node.
What are nodes and clients?
A "node" is any instance of Ethereum client software that is connected to other computers also running Ethereum software, forming a network. A client is an implementation of Ethereum that verifies data against the protocol rules and keeps the network secure.
Post-Merge Ethereum consists of two parts: the execution layer and the consensus layer. Both layers are run by different client software. On this page, we'll refer to them as the execution client and consensus client.
- The execution client (also known as the Execution Engine, EL client or formerly the Eth1 client) listens to new transactions broadcasted in the network, executes them in EVM, and holds the latest state and database of all current Ethereum data.
- The consensus client (also known as the Beacon Node, CL client or formerly the Eth2 client) implements the proof-of-stake consensus algorithm, which enables the network to achieve agreement based on validated data from the execution client.
Before The Merge, consensus and execution layer were separate networks, with all transactions and user activity on the Ethereum happening at what is now the execution layer. One client software provided both execution environment and consensus verification of blocks produced by miners. The consensus layer, the Beacon Chain, has been running separately since December 2020. It introduced proof-of-stake and coordinated the network of validators based on data from the Ethereum network.
With the Merge, Ethereum transitions to proof-of-stake by connecting these networks. Execution and consensus clients work together to verify Ethereum's state.
Modular design with various software pieces working together is called encapsulated complexity(opens in a new tab). This approach makes it easier to execute The Merge seamlessly and enables the reuse of individual clients, for example, in the layer 2 ecosystem.
(opens in a new tab) Simplified diagram of a coupled execution and consensus client.
Both execution clients and consensus clients exist in a variety of programming languages developed by different teams.
Multiple client implementations can make the network stronger by reducing its dependency on a single codebase. The ideal goal is to achieve diversity without any client dominating the network, thereby eliminating a potential single point of failure. The variety of languages also invites a broader developer community and allows them to create integrations in their preferred language.
Learn more about client diversity.
What these implementations have in common is they all follow a single specification. Specifications dictate how the Ethereum network and blockchain functions. Every technical detail is defined and specifications can be found as:
- Originally, the Ethereum Yellow Paper(opens in a new tab)
- Execution specs(opens in a new tab)
- Consensus specs(opens in a new tab)
- EIPs(opens in a new tab) implemented in various network upgrades
Tracking nodes in the network
Multiple trackers offer a real-time overview of nodes in the Ethereum network. Note that due to the nature of decentralized networks, these crawlers can only provide a limited view of the network and might report different results.
- Map of nodes(opens in a new tab) by Etherscan
- Ethernodes(opens in a new tab) by Bitfly
- Ethereum Node Crawler(opens in a new tab)
- Nodewatch(opens in a new tab) by Chainsafe, crawling consensus nodes
If you want to run your own node, you should understand that there are different types of node that consume data differently. In fact, clients can run three different types of nodes: light, full and archive. There are also options of different sync strategies which enable faster synchronization time. Synchronization refers to how quickly it can get the most up-to-date information on Ethereum's state.
- Stores full blockchain data (although this is periodically pruned so a full node does not store all state data back to genesis)
- Participates in block validation, verifies all blocks and states.
- All states can be derived from a full node (although very old states are reconstructed from requests made to archive nodes).
- Serves the network and provides data on request.
Instead of downloading every block, light nodes download block headers. These headers only contain summary information about the contents of the blocks. Any other information required by the light node gets requested from a full node. The light node can then independently verify the data they receive against the state roots in the block headers. Light nodes enable users to participate in the Ethereum network without the powerful hardware or high bandwidth required to run full nodes. Eventually, light nodes might run on mobile phones or embedded devices. The light nodes do not participate in consensus (i.e. they cannot be miners/validators), but they can access the Ethereum blockchain with the same functionality and security guarantees as a full node.
Light clients are an area of active development for Ethereum and we expect to see new light clients for the consensus layer and execution layer soon. There are also potential routes to providing light client data over the gossip network(opens in a new tab). This is advantageous because the gossip network could support a network of light nodes without requiring full nodes to serve requests.
Ethereum does not support a large population of light nodes yet, but light node support is an area expected to develop rapidly in the near future. In particular, clients like Nimbus(opens in a new tab), Helios(opens in a new tab), and LodeStar(opens in a new tab) are currently heavily focused on light nodes.
- Stores everything kept in the full node and builds an archive of historical states. It is needed if you want to query something like an account balance at block #4,000,000, or simply and reliably test your own transactions set without mining them using tracing.
- This data represents units of terabytes, which makes archive nodes less attractive for average users but can be handy for services like block explorers, wallet vendors, and chain analytics.
Syncing clients in any mode other than archive will result in pruned blockchain data. This means, there is no archive of all historical states but the full node is able to build them on demand.
Learn more about Archive nodes.
Why should I run an Ethereum node?
Running a node allows you to directly, trustlessly and privately use Ethereum while supporting the network by keeping it more robust and decentralized.
Benefits to you
Running your own node enables you to use Ethereum in a private, self-sufficient and trustless manner. You don't need to trust the network because you can verify the data yourself with your client. "Don't trust, verify" is a popular blockchain mantra.
- Your node verifies all the transactions and blocks against consensus rules by itself. This means you don’t have to rely on any other nodes in the network or fully trust them.
- You can use an Ethereum wallet with your own node. You can use dapps more securely and privately because you won't have to leak your addresses and balances to random nodes. Everything can be checked with your own client. MetaMask(opens in a new tab), Frame(opens in a new tab), and many other wallets offer RPC-importing, allowing them to use your node.
- You can run and self-host other services which depend on data from Ethereum. For example, this might be a Beacon Chain validator, software like layer 2, infrastructure, block explorers, payment processors, etc.
- You can provide your own custom RPC endpoints(opens in a new tab). Publicly for the community or even privately hosted Ethereum endpoint enables people to use your node and avoid big centralized providers.
- You can connect to your node using Inter-process Communications (IPC) or rewrite the node to load your program as a plugin. This grants low latency, which helps a lot, e.g. when processing a lot of data using web3 libraries or when you need to replace your transactions as fast as possible (i.e. frontrunning).
- You can directly stake ETH to secure the network and earn rewards. See solo staking(opens in a new tab) to get started.
A diverse set of nodes is important for Ethereum’s health, security and operational resiliency.
- Full nodes enforce the consensus rules so they can’t be tricked into accepting blocks that don't follow them. This provides extra security in the network because if all the nodes were light nodes, which don't do full verification, validators could attack the network.
- In case of an attack which overcomes the crypto-economic defenses of proof-of-stake, a social recovery can be performed by full nodes choosing to follow the honest chain.
- More nodes in the network result in a more diverse and robust network, the ultimate goal of decentralization, which enables a censorship-resistant and reliable system.
- They provide access to blockchain data for lightweight clients that depend on it. In high peaks of usage, there need to be enough full nodes to help light nodes sync. Light nodes don't store the whole blockchain, instead they verify data via the state roots in block headers. They can request more information from blocks if they need it.
If you run a full node, the whole Ethereum network benefits from it.
Running your own node
Interested in running your own Ethereum client?
For a beginner-friendly introduction visit our run a node page to learn more.
If you're more of a technical user, dive into more details and options on how to spin up your own node.
Setting up your own node can cost you time and resources but you don’t always need to run your own instance. In this case, you can use a third party API provider. For an overview of using these services, check out nodes as a service.
If somebody runs an Ethereum node with a public API in your community, you can point your wallets to a community node via Custom RPC and gain more privacy than with some random trusted third party.
On the other hand, if you run a client, you can share it with your friends who might need it.
Execution clients (formerly 'Eth1 clients')
The Ethereum community maintains multiple open-source execution clients (previously known as 'Eth1 clients', or just 'Ethereum clients'), developed by different teams using different programming languages. This makes the network stronger and more diverse. The ideal goal is to achieve diversity without any client dominating to reduce any single points of failure.
This table summarizes the different clients. All of them pass client tests(opens in a new tab) and are actively maintained to stay updated with network upgrades.
|Client||Language||Operating systems||Networks||Sync strategies||State pruning|
|Geth(opens in a new tab)||Go||Linux, Windows, macOS||Mainnet, Sepolia, Goerli||Snap, Full||Archive, Pruned|
|Nethermind(opens in a new tab)||C#, .NET||Linux, Windows, macOS||Mainnet, Sepolia, Goerli, and more||Snap (without serving), Fast, Full||Archive, Pruned|
|Besu(opens in a new tab)||Java||Linux, Windows, macOS||Mainnet, Sepolia, Goerli, and more||Snap, Fast, Full||Archive, Pruned|
|Erigon(opens in a new tab)||Go||Linux, Windows, macOS||Mainnet, Sepolia, Goerli, and more||Full||Archive, Pruned|
Note that OpenEthereum has been deprecated(opens in a new tab) and is no longer being maintained. Use another client implementation!
For more on supported networks, read up on Ethereum networks.
Each client has unique use cases and advantages, so you should choose one based on your own preferences. Diversity allows implementations to be focused on different features and user audiences. You may want to choose a client based on features, support, programming language, or licences.
Hyperledger Besu is an enterprise-grade Ethereum client for public and permissioned networks. It runs all of the Ethereum Mainnet features, from tracing to GraphQL, has extensive monitoring and is supported by ConsenSys, both in open community channels and through commercial SLAs for enterprises. It is written in Java and is Apache 2.0 licensed.
Besu's extensive documentation(opens in a new tab) will guide you through all details on its features and setups.
Erigon, formerly known as Turbo‐Geth, started as a fork of Go Ethereum oriented toward speed and disk‐space efficiency. Erigon is a completely re-architected implementation of Ethereum, currently written in Go but with implementations in other languages under development. Erigon's goal is to provide a faster, more modular, and more optimized implementation of Ethereum. It can perform a full archive node sync using around 2TB of disk space, in under 3 days.
Go Ethereum (Geth for short) is one of the original implementations of the Ethereum protocol. Currently, it is the most widespread client with the biggest user base and variety of tooling for users and developers. It is written in Go, fully open source and licensed under the GNU LGPL v3.
Learn more about Geth in its documentation(opens in a new tab).
Nethermind is an Ethereum implementation created with the C# .NET tech stack, licensed with LGPL-3.0, running on all major platforms including ARM. It offers great performance with:
- an optimized virtual machine
- state access
- networking and rich features like Prometheus/Grafana dashboards, seq enterprise logging support, JSON RPC tracing, and analytics plugins.
Nethermind also has detailed documentation(opens in a new tab), strong dev support, an online community and 24/7 support available for premium users.
Consensus clients (formerly 'Eth2' clients)
There are multiple consensus clients (previously known as 'Eth2' clients) to support the consensus upgrades. They are running the Beacon Chain and will provide a proof-of-stake consensus mechanism to execution clients after The Merge.
|Lighthouse(opens in a new tab)||Rust||Linux, Windows, macOS||Beacon Chain, Goerli, Pyrmont, Sepolia, Ropsten, and more|
|Lodestar(opens in a new tab)||TypeScript||Linux, Windows, macOS||Beacon Chain, Goerli, Sepolia, Ropsten, and more|
|Nimbus(opens in a new tab)||Nim||Linux, Windows, macOS||Beacon Chain, Goerli, Sepolia, Ropsten, and more|
|Prysm(opens in a new tab)||Go||Linux, Windows, macOS||Beacon Chain, Gnosis, Goerli, Pyrmont, Sepolia, Ropsten, and more|
|Teku(opens in a new tab)||Java||Linux, Windows, macOS||Beacon Chain, Gnosis, Goerli, Sepolia, Ropsten, and more|
Lighthouse is a consensus client implementation written in Rust under the Apache-2.0 license. It is maintained by Sigma Prime and has been stable and production-ready since Beacon Chain genesis. It is relied upon by various enterprises, staking pools and individuals. It aims to be secure, performant and interoperable in a wide range of environments, from desktop PCs to sophisticated automated deployments.
Documentation can be found in Lighthouse Book(opens in a new tab)
More information can be found on our Lodestar website(opens in a new tab)