# Ethereum mainnet and testnets: separate networks for separate purposes

Ethereum mainnet is the production network. Testnets are separate networks used to try applications, validators and protocol changes without using mainnet ETH. A matching account address does not carry its balance or history from one network to another. Choose the test network for the activity you need, and verify its current support before following an older tutorial.

Evidence: [Ethereum networks](https://ethereum.org/en/developers/docs/networks/)

Canonical: https://degreesofsatoshi.com/encyclopedia/ethereum-mainnet-and-testnets/
Published: 2026-10-02
Substantively modified: 2026-10-02
Independently verified by an automated reviewer: 2026-10-02T19:27:58.939Z
Data current through: 2026-10-02

AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied.

## Key facts

- **Separate state:** Balances and transaction history belong to a particular network. ([Ethereum networks](https://ethereum.org/en/developers/docs/networks/))
- **Application testing:** Current documentation recommends Sepolia for application development. ([Ethereum networks](https://ethereum.org/en/developers/docs/networks/))
- **Validator testing:** Current documentation identifies Hoodi for validator and upgrade testing. ([Ethereum networks](https://ethereum.org/en/developers/docs/networks/))

## Different environments answer different questions

A public testnet lets developers rehearse interactions in a shared environment. A local development network can be created for fast controlled tests. Mainnet is where production balances and deployed applications operate.

Testing demonstrates behavior under the tested conditions. It does not guarantee that a contract is secure or that mainnet liquidity, permissions and other dependencies match the test setup.

Evidence: [Ethereum networks](https://ethereum.org/en/developers/docs/networks/)

## A test balance is not a mainnet deposit

Suppose a faucet sends 2 test ETH to an address on Sepolia. Selecting Ethereum mainnet in the wallet will not reveal those 2 units there. Each network maintains its own account state, even where the same key produces the same address.

Deployments are separate too. A contract address in a test guide must be checked against the chain the guide uses.

Evidence: [Ethereum networks](https://ethereum.org/en/developers/docs/networks/)

## Test networks can be replaced

As of the primary documentation retrieved on 2 October 2026, Sepolia serves application testing and Hoodi supports open validator testing. Older networks such as Holesky are deprecated in that documentation.

Use the current network guide and separate test accounts from valuable mainnet use. A tutorial’s chain name, endpoint and faucet should all refer to the same supported environment.

Evidence: [Ethereum networks](https://ethereum.org/en/developers/docs/networks/)

## Questions

### Can testnet ETH be used to pay mainnet gas?

No. Testnet balances belong to their test network. Mainnet gas requires the funds or supported payment arrangement applicable on mainnet.

Evidence: [Ethereum networks](https://ethereum.org/en/developers/docs/networks/)

### Does changing a wallet network move my assets?

No. It changes which network’s state the wallet displays and uses. Moving assets is a separate operation.

Evidence: [Ethereum networks](https://ethereum.org/en/developers/docs/networks/)

## Claims and scope

### ethereum-mainnet-and-testnets-quick-answer

Ethereum mainnet is the production network. Testnets are separate networks used to try applications, validators and protocol changes without using mainnet ETH. A matching account address does not carry its balance or history from one network to another. Choose the test network for the activity you need, and verify its current support before following an older tutorial.

Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null}

### ethereum-mainnet-and-testnets-fact-separate-state

Separate state: Balances and transaction history belong to a particular network.

Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null}

### ethereum-mainnet-and-testnets-fact-application-testing

Application testing: Current documentation recommends Sepolia for application development.

Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null}

### ethereum-mainnet-and-testnets-fact-validator-testing

Validator testing: Current documentation identifies Hoodi for validator and upgrade testing.

Scope: {"collection":"ethereum","dataAsOf":"2026-10-02","blockHeight":null}

## Sources

- [Ethereum networks](https://ethereum.org/en/developers/docs/networks/) — ethereum.org contributors. Distinct network state and development/validator testing environments as of retrieval. Locator: Mainnet; Sepolia; Hoodi; testnet faucets. Retrieved: 2026-10-02T18:55:26.434Z.

## Revision history

- 2026-10-02: First publication after primary-source research and separate automated verification.

## Cite this entry

Degrees of Satoshi editorial project. “Ethereum mainnet and testnets: separate networks for separate purposes.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/ethereum-mainnet-and-testnets/